Random black screen during 1-2 seconds

Hi,

Since few days, i am facing a problem on all the 800G3 EliteDesk PC i got.

Randomly, i got a black screen, for a during of 1 or 2 second. It can happen 5 or 6 times per days.

I already tried to use HP SDM to upgrade every firmware/bios/drivers, it still happen.

I've changed on a single computer the DisplayPort cable to a HDMI cable, and it seems to correct the bug.

But currently, i am not able to change all the cable on all the computer, because i don't have enough connectors for HDMI.

Would you have an idea where the problem come from  ? How to solve it ?

Thanks,

Alexandre