can't uncheck iCloud photos option

Hello jrrozko,

Thanks for that info and for choosing the Apple Support Communities. If I understand correctly, you are unable to turn off iCloud Photos option in the Photos app on your Mac. To help isolate this, use safe mode to start up your Mac as it does the following things:

Verifies your startup disk and attempts to repair directory issues, if needed

Loads only required kernel extensions

Prevents Startup Items and Login Items from opening automatically

Disables user-installed fonts

Deletes font caches, kernel cache, and other system cache files

Log in to your user account and test the issue while in safe mode and then restart normally and test the issue again.

Use safe mode to isolate issues with your Mac

Graphics performance limited in macOS Recovery, safe mode, or Guest User mode

Get help with iCloud Photos

Cheers!