Same issue with my Sapphire Nitro+ 6800XT. Never had this issue with my other GPU prior to upgrading to this unit this last week.
5800x
msi b450 tomahawk max
superflower 850w psu gold
____
I've tried different settings in games and AMD Radeon software, new DP cable (Vesa Certified 1.4), reseating GPU and power connectors to/from PSU.
I've recently read that there's a conflicting issue with the AMD Audio driver + any other audio drive you have installed. So as of this post, I'm currently disabling the AMD Audio driver to see if this resolves anything.