[Bug] Specific /index route fails to render in Next.js 15.5.2 while other similar routes work correctly

### Link to the code that reproduces this issue https://github.com/childrentime/index-route-test ### To Reproduce In Next.js 15.5.2, the specific /index route fails to render with a WebSocket/HMR error, while other similar nested routes (like /index1, /index2, etc.) work perfectly fine. This appears to be a specific issue with the /index path rather than a general routing problem. Create a Next.js 15.5.2 project with Pages Router Create the following file structure: pages/ ├── index.tsx # Root page (/) ├── index/ │ └── index.tsx # Should serve /index route └── index1/ └── index.tsx # Serves /index1 route (works fine) Start the development server with next dev Navigate to /index1 - ✅ Works correctly Navigate to /index - ❌ Fails with rendering error ### Current vs. Expected behavior Expected Behavior The /index route should render the content from pages/index/index.tsx successfully Should behave identically to other nested routes like /index1 Actual Behavior Accessing /index results in a rendering failure with the following error: ot-reloader-pages.js:199:17) at eval (hot-reloader-pages.js:72:13) at WebSocket.handleMessage (websocke The page fails to render and shows a blank screen or error state Other routes like /index1 work without any issues ### Provide environment information ```bash Operating System: Platform: darwin Arch: arm64 Version: Darwin Kernel Version 23.1.0: Mon Oct 9 21:32:52 PDT 2023; root:xnu-10002.41.9~7/RELEASE_ARM64_T8122 Available memory (MB): 16384 Available CPU cores: 8 Binaries: Node: 20.11.1 npm: 10.2.4 Yarn: 1.22.21 pnpm: 10.15.0 Relevant Packages: next: 15.5.2 // Latest available version is detected (15.5.2). eslint-config-next: 15.5.2 react: 19.1.0 react-dom: 19.1.0 typescript: 5.9.2 Next.js Config: output: N/A ``` ### Which area(s) are affected? (Select all that apply) Pages Router ### Which stage(s) are affected? (Select all that apply) next dev (local)…