diff --git a/playwright/index.ts b/playwright/index.ts
index 9a98a55b6..8eb41f867 100644
--- a/playwright/index.ts
+++ b/playwright/index.ts
@@ -1,4 +1,4 @@
-import { test as baseTest, BrowserContext, ElectronApplication, Page } from '@playwright/test';
+import { test as baseTest, BrowserContext, ElectronApplication, Page, TestInfo } from '@playwright/test';
 import * as path from 'path';
 import * as os from 'os';
 import * as fs from 'fs';
@@ -19,12 +19,107 @@ async function recursiveCopy(src: string, dest: string) {
 
   for (const file of files) {
     if (!file.isFile()) continue;
-    const fullPath = path.join(src, file.name);
-    const fullDestPath = path.join(dest, file.name);
+    const parentDir = file.parentPath || (file as any).path;
+    const fullPath = path.join(parentDir, file.name);
+    const relativePath = path.relative(src, fullPath);
+    const fullDestPath = path.join(dest, relativePath);
+    await fs.promises.mkdir(path.dirname(fullDestPath), { recursive: true });
     await fs.promises.copyFile(fullPath, fullDestPath);
   }
 }
 
+async function rewriteCollectionPaths(
+  userDataPath: string,
+  fileName: string,
+  pathKey: string,
+  pathMap: Map<string, string>
+) {
+  const filePath = path.join(userDataPath, fileName);
+  if (!await existsAsync(filePath)) return;
+
+  const content = await fs.promises.readFile(filePath, 'utf-8');
+  const data = JSON.parse(content);
+  if (!Array.isArray(data.collections)) return;
+
+  let changed = false;
+  for (const entry of data.collections) {
+    const mapped = pathMap.get(entry[pathKey]);
+    if (mapped) {
+      entry[pathKey] = mapped;
+      changed = true;
+    }
+  }
+
+  if (changed) {
+    await fs.promises.writeFile(filePath, JSON.stringify(data, null, 2), 'utf-8');
+  }
+}
+
+async function isolateCollections(
+  userDataPath: string,
+  createTmpDir: (tag?: string) => Promise<string>
+) {
+  const prefsPath = path.join(userDataPath, 'preferences.json');
+  if (!await existsAsync(prefsPath)) return;
+
+  const content = await fs.promises.readFile(prefsPath, 'utf-8');
+  const prefs = JSON.parse(content);
+
+  if (Array.isArray(prefs.lastOpenedCollections) && prefs.lastOpenedCollections.length > 0) {
+    const pathMap = new Map<string, string>(); // original -> isolated
+    const newPaths: string[] = [];
+    for (const collPath of prefs.lastOpenedCollections) {
+      if (!await existsAsync(collPath)) {
+        newPaths.push(collPath);
+        continue;
+      }
+
+      // Copy the parent directory of the collection so that relative
+      // paths (e.g. ../protos/, ../client.pfx) still resolve correctly.
+      // The collection subdirectory itself becomes the isolated copy.
+      const parentDir = path.dirname(collPath);
+      const collBaseName = path.basename(collPath);
+      const tmpParentDir = await createTmpDir('collection');
+      await recursiveCopy(parentDir, tmpParentDir);
+      const tmpCollDir = path.join(tmpParentDir, collBaseName);
+
+      pathMap.set(collPath, tmpCollDir);
+      newPaths.push(tmpCollDir);
+    }
+    prefs.lastOpenedCollections = newPaths;
+    await fs.promises.writeFile(prefsPath, JSON.stringify(prefs, null, 2), 'utf-8');
+
+    // Rewrite collection paths in user-data JSON files that reference
+    // collections by their original filesystem path so lookups still
+    // match after isolation.
+    if (pathMap.size > 0) {
+      await rewriteCollectionPaths(userDataPath, 'collection-security.json', 'path', pathMap);
+      await rewriteCollectionPaths(userDataPath, 'ui-state-snapshot.json', 'pathname', pathMap);
+    }
+  }
+}
+
+async function withTracing(
+  context: BrowserContext,
+  page: Page,
+  testInfo: TestInfo,
+  use: (page: Page) => Promise<void>
+) {
+  const tracingOptions = (testInfo as any)._tracing.traceOptions();
+  if (tracingOptions) {
+    const tracePath = testInfo.outputPath(`trace-${testInfo.testId}.zip`);
+    try {
+      await context.tracing.start({ screenshots: true, snapshots: true, sources: true });
+    } catch (e) { }
+    await context.tracing.startChunk();
+    await use(page);
+    await context.tracing.stopChunk({ path: tracePath });
+    await testInfo.attach('trace', { path: tracePath });
+  } else {
+    await use(page);
+  }
+}
+
 export const test = baseTest.extend<
   {
     context: BrowserContext;
@@ -82,6 +177,10 @@ export const test = baseTest.extend<
             });
             await fs.promises.writeFile(path.join(userDataPath, file), content, 'utf-8');
           }
+
+          // Copy referenced collections to temp dirs so parallel workers
+          // never share the same filesystem paths
+          await isolateCollections(userDataPath, createTmpDir);
         }
 
         const app = await playwright._electron.launch({
@@ -128,45 +227,21 @@ export const test = baseTest.extend<
     { scope: 'worker' }
   ],
 
-  context: async ({ electronApp }, use, testInfo) => {
+  context: async ({ electronApp }, use) => {
     const context = await electronApp.context();
-    const tracingOptions = (testInfo as any)._tracing.traceOptions();
-    if (tracingOptions) {
-      try {
-        await context.tracing.start({ screenshots: true, snapshots: true, sources: true });
-      } catch (e) { }
-    }
     await use(context);
   },
 
   page: async ({ electronApp, context }, use, testInfo) => {
     const page = await electronApp.firstWindow();
-    const tracingOptions = (testInfo as any)._tracing.traceOptions();
-    if (tracingOptions) {
-      const tracePath = testInfo.outputPath(`trace-${testInfo.testId}.zip`);
-      await context.tracing.startChunk();
-      await use(page);
-      await context.tracing.stopChunk({ path: tracePath });
-      await testInfo.attach('trace', { path: tracePath });
-    } else {
-      await use(page);
-    }
+    await withTracing(context, page, testInfo, use);
   },
 
   newPage: async ({ launchElectronApp }, use, testInfo) => {
     const app = await launchElectronApp();
     const context = await app.context();
     const page = await app.firstWindow();
-    const tracingOptions = (testInfo as any)._tracing.traceOptions();
-    if (tracingOptions) {
-      const tracePath = testInfo.outputPath(`trace-${testInfo.testId}.zip`);
-      await context.tracing.start({ screenshots: true, snapshots: true, sources: true });
-      await use(page);
-      await context.tracing.stop({ path: tracePath });
-      await testInfo.attach('trace', { path: tracePath });
-    } else {
-      await use(page);
-    }
+    await withTracing(context, page, testInfo, use);
   },
 
   reuseOrLaunchElectronApp: [
@@ -231,19 +306,7 @@ export const test = baseTest.extend<
 
     const context = await app.context();
     const page = await app.firstWindow();
-    const tracingOptions = (testInfo as any)._tracing.traceOptions();
-    if (tracingOptions) {
-      const tracePath = testInfo.outputPath(`trace-${testInfo.testId}.zip`);
-      try {
-        await context.tracing.start({ screenshots: true, snapshots: true, sources: true });
-      } catch (e) { }
-      await context.tracing.startChunk();
-      await use(page);
-      await context.tracing.stopChunk({ path: tracePath });
-      await testInfo.attach('trace', { path: tracePath });
-    } else {
-      await use(page);
-    }
+    await withTracing(context, page, testInfo, use);
   }
 });
 
diff --git a/tests/collection/close-all-collections/close-all-collections.spec.ts b/tests/collection/close-all-collections/close-all-collections.spec.ts
index 94f878199..faa09ebaf 100644
--- a/tests/collection/close-all-collections/close-all-collections.spec.ts
+++ b/tests/collection/close-all-collections/close-all-collections.spec.ts
@@ -1,7 +1,5 @@
-import { execSync } from 'child_process';
 import { test, expect } from '../../../playwright';
 import { Page, ElectronApplication } from '@playwright/test';
-import path from 'path';
 import { openCollection } from '../../utils/page/actions';
 import { buildCommonLocators } from '../../utils/page/locators';
 
@@ -20,11 +18,6 @@ const restartAppAndGetLocators = async (restartApp: (options?: { initUserDataPat
 // The CollectionsHeader component (with collections-header-actions-menu-close-all) is not rendered in workspace mode
 // The "Remove from workspace" flow is different from the old "Close collection" flow
 test.describe.skip('Close All Collections', () => {
-  test.afterAll(async () => {
-    // Reset the request file to the original state after saving changes
-    execSync(`git checkout -- "${path.join(__dirname, 'fixtures', 'collections', 'collection 1', 'test-request.bru')}"`);
-  });
-
   test('should show/hide close all icon based on hover state', async ({ pageWithUserData: page }) => {
     const locators = buildCommonLocators(page);
 
diff --git a/tests/environments/import-environment/bruno-env-import/collection-env-import/collection-env-import.spec.ts b/tests/environments/import-environment/bruno-env-import/collection-env-import/collection-env-import.spec.ts
index fd18920df..0e991eaab 100644
--- a/tests/environments/import-environment/bruno-env-import/collection-env-import/collection-env-import.spec.ts
+++ b/tests/environments/import-environment/bruno-env-import/collection-env-import/collection-env-import.spec.ts
@@ -1,19 +1,13 @@
 import { test, expect } from '../../../../../playwright';
 import path from 'path';
-import fs from 'fs';
 
 test.describe.serial('Collection Environment Import Tests', () => {
-  test('should import single collection environment', async ({ pageWithUserData: page }) => {
+  test('should import single collection environment', async ({ restartApp }) => {
+    const app = await restartApp();
+    const page = await app.firstWindow();
     const singleEnvFile = path.join(__dirname, '../../../fixtures/environment-exports/local.json');
-    const collectionPath = path.join(__dirname, 'fixtures/collection');
-    const environmentsPath = path.join(collectionPath, 'environments');
-
-    await test.step('Clean up existing environments and open collection', async () => {
-      // Clean up any existing environments folder before test
-      if (fs.existsSync(environmentsPath)) {
-        fs.rmSync(environmentsPath, { recursive: true, force: true });
-      }
 
+    await test.step('Open collection', async () => {
       // Open the collection from sidebar
       await page.locator('#sidebar-collection-name').filter({ hasText: 'Environment Import Test Collection' }).click();
     });
@@ -49,26 +43,14 @@ test.describe.serial('Collection Environment Import Tests', () => {
       await envTab.hover();
       await envTab.getByTestId('request-tab-close-icon').click();
     });
-
-    await test.step('Clean up after test', async () => {
-      // Clean up any existing environments folder before test
-      if (fs.existsSync(environmentsPath)) {
-        fs.rmSync(environmentsPath, { recursive: true, force: true });
-      }
-    });
   });
 
-  test('should import multiple collection environments', async ({ pageWithUserData: page }) => {
+  test('should import multiple collection environments', async ({ restartApp }) => {
+    const app = await restartApp();
+    const page = await app.firstWindow();
     const multiEnvFile = path.join(__dirname, '../../../fixtures/environment-exports/bruno-collection-environments.json');
-    const collectionPath = path.join(__dirname, 'fixtures/collection');
-    const environmentsPath = path.join(collectionPath, 'environments');
-
-    await test.step('Clean up existing environments and open collection', async () => {
-      // Clean up any existing environments folder before test
-      if (fs.existsSync(environmentsPath)) {
-        fs.rmSync(environmentsPath, { recursive: true, force: true });
-      }
 
+    await test.step('Open collection', async () => {
       // Open the collection from sidebar
       await page.locator('#sidebar-collection-name').filter({ hasText: 'Environment Import Test Collection' }).click();
     });
@@ -130,12 +112,5 @@ test.describe.serial('Collection Environment Import Tests', () => {
       await envTab.hover();
       await envTab.getByTestId('request-tab-close-icon').click();
     });
-
-    await test.step('Clean up after test', async () => {
-      // Clean up any existing environments folder before test
-      if (fs.existsSync(environmentsPath)) {
-        fs.rmSync(environmentsPath, { recursive: true, force: true });
-      }
-    });
   });
 });
diff --git a/tests/protobuf/manage-protofile.spec.ts b/tests/protobuf/manage-protofile.spec.ts
index e96d17019..eb96c75ea 100644
--- a/tests/protobuf/manage-protofile.spec.ts
+++ b/tests/protobuf/manage-protofile.spec.ts
@@ -1,27 +1,6 @@
-import path from 'path';
 import { test, expect } from '../../playwright';
-import { closeAllCollections } from '../utils/page';
-import fs from 'fs';
-
-const COLLECTION_PATH = path.join(__dirname, 'collection', 'bruno.json');
-const BACKUP_PATH = path.join(__dirname, 'collection', 'bruno.json.backup');
-import { execSync } from 'child_process';
 
 test.describe('manage protofile', () => {
-  test.beforeAll(async () => {
-    // Backup original file
-    if (fs.existsSync(COLLECTION_PATH)) {
-      fs.copyFileSync(COLLECTION_PATH, BACKUP_PATH);
-    }
-  });
-
-  test.afterAll(async ({ pageWithUserData: page }) => {
-    // Close all collections
-    await closeAllCollections(page);
-    // Reset the collection request file to the original state
-    execSync(`git checkout -- ${path.join(__dirname, 'collection', 'bruno.json')}`);
-  });
-
   test('protofiles, import paths from bruno.json are visible in the protobuf settings', async ({ pageWithUserData: page }) => {
     await page.locator('#sidebar-collection-name').filter({ hasText: 'Grpcbin' }).click();
 
diff --git a/tests/request/headers/header-validation.spec.ts b/tests/request/headers/header-validation.spec.ts
index 4c5c62fab..9bf2f8975 100644
--- a/tests/request/headers/header-validation.spec.ts
+++ b/tests/request/headers/header-validation.spec.ts
@@ -51,9 +51,8 @@ test.describe.serial('Header Validation', () => {
       const headerRow = page.locator('table tbody tr').first();
       const nameCell = getTableCell(headerRow, 0);
 
-      // Clear and enter a valid header name
-      await nameCell.locator('.CodeMirror').click();
-      await page.keyboard.press('Meta+a');
+      // Clear and enter a valid header name - use triple-click to select all (works cross-platform)
+      await nameCell.locator('.CodeMirror').click({ clickCount: 3 });
       await nameCell.locator('textarea').fill('Valid-Header');
 
       // Verify the error icon is not visible
diff --git a/tests/response-examples/create-example.spec.ts b/tests/response-examples/create-example.spec.ts
index b2d56bdec..395c40da5 100644
--- a/tests/response-examples/create-example.spec.ts
+++ b/tests/response-examples/create-example.spec.ts
@@ -1,14 +1,7 @@
-import { execSync } from 'child_process';
 import { test, expect } from '../../playwright';
-import path from 'path';
 import { clickResponseAction } from '../utils/page/actions';
 
 test.describe.serial('Create and Delete Response Examples', () => {
-  test.afterAll(async () => {
-    // Reset the collection request file to the original state
-    execSync(`git checkout -- ${path.join(__dirname, 'fixtures', 'collection', 'create-example.bru')}`);
-  });
-
   test('should create a response example from response bookmark', async ({ pageWithUserData: page }) => {
     await test.step('Open collection and request', async () => {
       await page.locator('#sidebar-collection-name').filter({ hasText: 'collection' }).click();
diff --git a/tests/response-examples/edit-example.spec.ts b/tests/response-examples/edit-example.spec.ts
index 41abc3b9d..cccf92875 100644
--- a/tests/response-examples/edit-example.spec.ts
+++ b/tests/response-examples/edit-example.spec.ts
@@ -1,14 +1,7 @@
 import { test, expect } from '../../playwright';
-import { execSync } from 'child_process';
-import path from 'path';
 import { clickResponseAction } from '../utils/page/actions';
 
 test.describe.serial('Edit Response Examples', () => {
-  test.afterAll(async () => {
-    // Reset the collection request file to the original state
-    execSync(`git checkout -- ${path.join(__dirname, 'fixtures', 'collection', 'edit-example.bru')}`);
-  });
-
   test('should enter edit mode and show editable fields when edit button is clicked', async ({ pageWithUserData: page }) => {
     await test.step('Open collection and request', async () => {
       await page.locator('#sidebar-collection-name').getByText('collection').click();
diff --git a/tests/response-examples/menu-operations.spec.ts b/tests/response-examples/menu-operations.spec.ts
index f287f280c..0e17bf27b 100644
--- a/tests/response-examples/menu-operations.spec.ts
+++ b/tests/response-examples/menu-operations.spec.ts
@@ -1,14 +1,8 @@
 import { test, expect } from '../../playwright';
-import { execSync } from 'child_process';
-import path from 'path';
 import { clickResponseAction } from '../utils/page/actions';
 
 test.describe.serial('Response Example Menu Operations', () => {
   test.setTimeout(1 * 60 * 1000); // 1 minute for all tests in this describe block, default is 30 seconds.
-  test.afterAll(async () => {
-    // Reset the collection request file to the original state
-    execSync(`git checkout -- ${path.join(__dirname, 'fixtures', 'collection', 'menu-operations.bru')}`);
-  });
 
   test('should clone a response example via three dots menu', async ({ pageWithUserData: page }) => {
     await test.step('Open collection and request', async () => {