B450i Fatality - At Wit's End

Hello all,

I am having an extremely frustrating time with my B450i Fatality and I'm really at my wit's end. I have no idea what is causing this issue.

What the issue is: Using an APU (in my case either a 2400g or 5600g), my display will flicker, turn black, or briefly artifact. When I enable HDMI Deep Color (primary display is an LG 55CX Oled), it does the same thing on steroids...almost freezing the TV entirely, at times.

What have I tried?

Well, I have had the motherboard RMA'd and I'm sitting here with the replacement. Both the replacement board and the old board do the same thing. I've tried two apus (2400g, 5600g), three ram sets all running at stock (either 3600 or 2666) or underclocked. I have tried two different displays, three different hdmi ports, three different cables, two different PSUs. I have tried two different nvme boot drives. I have reinstalled windows countless times and am running the latest version of the adrenalin drivers. I have tried older adrenalin drivers. The bios is the most recent version.

Why do I believe it is the board?
Both CPUs have been placed in a low end B450 gigabyte board and an X570 Taichi and have output video just fine. HD Color can be turned on. Freesync Premium can be enabled. No issues. On the Fatality, I can't even run stock settings (hdr off), 60hz, without encountering artifacting or black screen flashes. Albeit they are far fewer, they do occur and will make their presence felt during video playback.

I am at a loss. I have emailed customer support letting them know the replacement motherboard is exhibiting the same issues that the original and whether or not I should just send back both at the same time.

If anyone has any idea, I would be eternally grateful.