This has been an issue I’ve seen on the forums as of late. Search and pay attention to the ones with replies by @Mattches. I belive one of the things you can try is to turn off brave shields and try logging back into gmail.
PLEASE NOTE If you uninstall the browser, you will lose all tokens not transfered to a verified wallet and it will count against your 4 device limit.
Here is a thread to get you started.