Nvidia: weird behavior between 2 sessions

I recently (at last) installed nvidia driver without problem (CL: 35930, thinkpad P1, Xeon 12, quadro P2000).
Many thanks for the excellent tuto.
I have 2 sessions. When I move from one to the other, the desktop has a weird behavior: icons and voyels are missing (see pictures).
Does somebody has encountered this situation or has any idea to solve this?


Nobody was interested in solving that issue.
I found why, but I didn’t solve it because it’s a nvidia driver issue.
It happens when I connect the pc to a monitor.
The nvidia driver can’t manage the switching session properly.