reproduction:
create new file with command + n
save as test.ipynb
watch it get auto-renamed to test.ipynb.i extension and then you have to manually change it back to get the ipynb file extension/formatting etc. Didn’t find anything in vscode issues after a brief search and google was totally useless for searching the exact string “ipynb.i” unfortunately 
this might be a worse issue than i thought… might be something about macos? unclear though, has anyone else replicated this?
Version: 0.41.3
VSCode Version: 1.91.1
Commit: 51c8aff7cb5a89f4a0e462fbacab938bdbfaf140
Date: 2024-09-25T17:13:50.377Z (2 wks ago)
Electron: 29.4.0
ElectronBuildId: undefined
Chromium: 122.0.6261.156
Node.js: 20.9.0
V8: 12.2.281.27-electron.0
OS: Darwin arm64 24.0.0
Having the exact same issue here
Is there any way to fix this???
I have the exact same problem but I’m on vanilla VS Code version 1.94.2 (not Cursor).
probably a vs code issue then, although I haven’t found anyone else report this in github issues or anything. fwiw @type one fix is to cmd + b, create a new file by right-clicking and then naming it there lol