Googling a bit more… some say hot-swapping HDMI cables is a no-no… OK, I’ll try not to hot swap anymore… lol… I’ve done it quite a few times.
My PC is using a Wavlink DisplayLink USB C HDMI and DP docking station. Using Display Port (DP) to my work monitor and HDMI to AVR. So, the blackout happened when was watching stream football last Saturday. But yesterday, I ran youtube for over an hour without any blackouts.
Anyway, I’ll continue using as normal. Hopefully, problems won’t happen again. If it does, maybe I’ll send the Denon to service center (hopefully before end of warranty)