Play and preview problem in premiere pro 2020

Hi

When I play any footage in the monitor window, It appears to be accelerated, and the sound is jerky. It do the same with any kind of media encoding. I tried to uninstall premiere 2020 and reinstall again. My PC has a I7 processor, 16Gb Ram, with a Nvidia 2060 super video card, and GPU acceleration is activated. 

When I export the sequence, the video is playing fine in any video player.

Thanks for your help,

Philippe