Did a little digging around and there's some things you can try if you haven't already. Unfortunately this seems to be a random issue that just starts happening

Disable all overlays. Shadowplay, Discord, Steam, etc.
You can try reverting back to old Nvidia Drivers (make sure you do clean installs if you do)
Disable dx11 in launcher

Someone said changing the scaling from display to GPU fixed it for them. Nvidia control panel > Ajust Desktop Size and position > perform scaling on:
(I don't have a display setting here, so it's defaulted to GPU)



Some people have had success with underclocking their GPU using MSI Afterburner or Nvidia Precision
https://www.reddit.com/r/ffxiv/comme...eb2x&context=3
https://www.youtube.com/watch?v=dPfZfQk38wM&t=195s


Here is a long list of things people have tried.
https://www.reddit.com/r/ffxiv/comme...eb2x&context=3