I have a couple of suggestions that you could try.
- Check if disabling
Hardware Acceleration
viabrave://settings/system
resolves the issue. - Check if temporarily disabling
Brave Shields
via the icon in the address bar resolves the issue. - Check if clearing all-time cache via
brave://settings/clearBrowserData
resolves the issue. - Check if the issue is present in a fresh (test) user profile. Make sure to close all windows of the current user profile when performing tests in the fresh (test) user profile, i.e, only windows from the fresh (test) user profile must be active during your tests.