Help ! Program and Source monitors are blank with CC2020

Hello, 

I have just installed the Première Pro CC 2020 update  and after a few hours working well, suddenly both the Première Pro Source and Program monitors went blank. When shutting down and restarting Première both monitors work for a while, then they go blank again. This happens in a recurrent mode. Sometimes Première crashes as well.

I have not uninstalled the CC2019 version and when I open an earlier version of the same project under CC 2019 both monitors work.

I have 2 Graphic Cards GeForce GTX 1080Ti and I have installed the latest pilot version  441.28

I see that there are many posts about blank monitors issue. But since my monitors work with CC2019 and don't work well with CC 2020, I feel the problem is most likely with CC 2020.  I would like to be able to work with CC 2020 and not be stuck with CC 2019.

Can someone help me?

Here are my settings:

Processor :AMD Ryzen Threadripper 1950X 16 Core

RAM 64 GB

GeForce GTX 1080Ti *2 pilot 441.28

Windows 10 64 bits pro

Thanks  in advance