Stuttering on DX12

Hey everybody.

Im running a 7900xtx with stock settings for testing purposes and all "enhancements" like anti lag and enhanced sync disabled. Ofc all other scaling and frame gen is disabled as well.
CPU: 7800x3d
RAM: 64gb 5600mhz CL28
Game is on an m2 ssd
Win 11

I have 3 different monitors attatched, one plugged into a 2070 super and all set to 140hz, 140hz and 70hz.
Before anybody mentions the multi monitor stutter issues windows has become famous for, the stutter persists with just 2 140hz monitors or 1 140/144 hz monitor.

The issue did NOT happen when playing on dx11 in fullscreen...

Now with dx12, rtss support is entirely nuked for the time being, locking the game at a stable 45-50 fps for no reason and simply disabling rtss is not enough, it needs to be turned off entirely.

Now the actual issue:
When playing on higher FPS, 300, its just stuttering all over the place. The FPS are reported ingame as stable 300 but its borderline unplayable. Same thing happens at anything above monitor refreshrate. When running at 140 with the start opton fps_max 140 its smooth for the most part but has some stutter every now and then, every few seconds.
Feels like someone turned down the FPS to 60-70 while playing.
Full screen optimization is disabled.

Does anybody know of any issue regarding the hardware or the setup that could cause this, or a more specific area that causes problems like this?
If i can still run the game in dx11, ill just do that since it had 0 issues.

Edit: It seems to be working fine when enabling windows's windowed application optimizations, was disadvantagous when using dx11 but now seems to do the trick. RTSS still broken tho