20m hdmi 2.1 certified cable + LG 32GS95UE-B

Hi,

I am struggling to identify the root cause of the random instant screen on/off on resolution 4k@120Hz with ASUS 3080 with HDMI 2.1 port.

With the same cable and monitor but with Sapphire Nitro+ 5700 XT connected to its HDMI 2.0b on resolution 4k@120hz everything works without any problem.

With the same cable and ASUS 3080 and LG G1 65inch tv on resolution 4k@120hz everything works without any problem.

I was testing various parameters through CRU excellent tool but no luck. If there any way to troubleshoot the behaviour?

The cable is HDMI 2.1 20meter optical certified and I have already tested to use HDMI 5v voltage inserter through USB3 port but no luck.

Thank you so much for your time,
Mike