Choppy playback when Premiere window is active, plays fine when in background.

[Orfeas5DD1]

I am getting a really strange behavior in my new workstation. After media import, playback on the source monitor & timeline is choppy (like 3FPS choppy). But at the moment i select another window to come in the foreground (lets say file browser, or task manager, or whatever), playback normalize. If i select again the Premiere window problem returns. 

Adobe Premiere 14.7.0 build 23

Rendered: Mercury (CUDA)

CPU: AMD Threadripper 3960X

RAM: 64GB 3600mhz CL16

GPU: RTX 3080

Any help would be appreciated, i am at a loss.

[Orfeas5DD1]

Forgot to mention: 

OS: Windows 10 Pro 20H2

Driver: Nvidia 460.89 Studio Driver

Monitor: Samsung Odyssey G9 

[Orfeas5DD1 · Accepted solution]

SOLVED: 

G-Sync messes with the app. Enable G-Sync only for full screen applications or try setting a program specific rule on Nvidia Control panel.