Geforce 3080 HDMI 2.1 Intermittent black screen

I have recently got a new 34 3440x1440 240hz QD Oled monitor and everything works perfect with DP 1.4. But since my card and monitor support HDMI 2.1 i decided to try it out.
Unfortunately, very randomly i experience a black screen for 2-3 seconds then the screen comes back. Usually this happens while at the desktop and so far has only happened only once while gaming.
I have tried two different HDMI 2.1 cables- one coming with the monitor and another one brand new from a reputable brand. Both cables are 2.1 48gbps.
Also tried to play with the settings in Nvidia Control Panel- switching the color depth from 8bit/10bit, etc, but nothing helped.
I really want to make it working and i am sure the card is working fine, so not a hardware issue with it.
Anyone has any idea ?