VSCode Pylance highlighting not showing when there is too many files

This is current setting.JSON

{"remote.autoForwardPortsSource": "output","python.analysis.completeFunctionParens": true,"python.languageServer": "Pylance","python.analysis.diagnosticMode": "workspace","python.analysis.exclude": ["**/data/**","**/tmp/**","**/output/**","**/dataset/**","**/ckpts/**","**/work_dirs/**","**/assets/**","**/docs/**","**/figs/**","**/resources/**","**/.git/**","**/.github/**",    ],"files.watcherExclude": {"**/.git/**": true,"**/tmp/**": true,"**/ouput/**": true,"**/others/**": true,"**/data/**": true,"**/.github/**": true,    },"explorer.autoReveal": false}

Pylance is wokring well by showing description of library like this:

however, the problem is it is not highlighting the code properly.

The problem is solved if I delete whole project and highlight comes back. But, whenever number of files in project is getting larger, this happens again.

Any help would be greately appreciate!