What is your refresh rate set at? I have only found one solution (that worked) on a Reddit post, but have been unable to find that post again.
I changed the refresh rate of my card from 59/60hz to initially 24hz, then to 30hz. I haven't extensively tested the 30hz, except for a 10 to 20 minute window (no issues), but I know that at 24hz the audio cutting completely disappeared. Occasional video refresh clean ups, but the audio cutting out was completely eliminated.
There seems to be an issue with 60hz being processed for AMD Radeon cards to 4K devices. Not sure if its an HDCP mismatch or what. I also turned off HDMI Assurance on AMD Adrenaline software, which also reduced audio skips.
I'm going to post this answer around. Hopefully AMD will clear this up.
HP 8100 Elite, I5 4th Gen, 8 GB, LG 65' OLED, Integra 4.2, Windows 10