#1 - in your nVidia settings, do you have Vertical Synch turned off?
#2 - this sounds like a known issue. I find that if I switch to another application, that PM refreshes itself on the other monitor while I'm in the other app (browser, e.g.) ... also there is some bug that causes drawings to be refreshed up to 3 times. It is normally not visible, but on my cover sheet that has several large (10's of thousands of lines) vectorial hatched perspective line drawings, I can watch them get repainted over and over. Reported during beta testing.
Karl
AC 28 USA and earlier • macOS Sequoia 15.3, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB
One of the forum moderators