This sounds like the known issue with the 460-series Nvidia drivers.
https://us.forums.blizzard.com/en/wow/t/main-thread-nvidia-460xx-driver-flickering/766732
Reverting to the latest 458.xx corrects it.
This sounds like the known issue with the 460-series Nvidia drivers.
https://us.forums.blizzard.com/en/wow/t/main-thread-nvidia-460xx-driver-flickering/766732
Reverting to the latest 458.xx corrects it.