I used to have problems and visual glitches with text in flatpaks (like VS code, or Spotify, the text would be bugged), but as of the latest drivers that is fixed.
From my experience on Fedora, my advice is that after a new kernel installs, don’t restart immediately, give it a minute or two to build the nvidia drivers for that kernel. If you are signing them for secure boot i guess the recommended wait is 5 minutes.