codespace editor error

[SharpMoneyTips]

Bug: Validation/highlighting missing in Codespaces

Hi,
After editing a Prisma schema with copy-paste in GitHub Codespaces, all TypeScript validation and error highlighting disappeared from the editor.

• No errors or messages appear, but no code mistakes are underlined or highlighted anymore.
• I have tried restarting Codespaces, resetting settings, and switching branches.
• Screenshot attached.
• GitHub support redirected me here: https://github.com/microsoft/vscode/issues

VS Code Version: Codespaces default
OS Version: Codespaces (Ubuntu)

Steps to Reproduce:

1. Open a Prisma schema or TypeScript file in Codespaces.
2. Select (highlight) a block of code/text using touchpad.
3. Copy and paste the text.
4. Grid-like artifacts appeared, and after that, all validation was gone.

Screenshots:
*