2x U3223QE, losing sync on DisplayPort input

Hello!

I have to monitors plugged into Nvidia RTX 4090 Desktop via DP cables. I use monitors mostly for architecture work. The first monitor I bought 1 year ago, the other one just recently. Both monitors are acting extremely weird. When there is a certain video stream from HBO, Cinemax, ... , and sometimes from the Youtube, the monitors lose sync. There is static on the screen for a second or two, then there is no DP signal from the device, then they are going into the standby mode. I have to unplug the cables and re-plug them. After that the monitors work fine until the next power up of the computer. The whole process is very frustrating.

I tried to solve the problem:

1. I plugged 3 different monitors into 4090 via DP and they were working just fine (an older HP, Samsung 4K and Benq 2K)

2. I replaced the DP cables for very expensive 8K cables. I tried both monitors on, one off and the other on, ... No difference.

3. I changed the source of power supply (different sockets, grounded, ...)

4. I rolled back Nvidia drivers, uninstalled them and made a clean install, updated firmware. No difference.

5. I updated firmware on both monitors to M3T105 and then rolled back to 104 and 103. And so on... All the possible combinations and no difference. It took me more then two days to test all the possibilities! I just can't believe that monitors in such a price range operate in this kind of malfunction.

Please solve the problem ASAP.

Thank you,

Luka Potokar