Ok so i had the same issues as everyone else, playing games through hdmi audio drops in and out
try this and it should work
go to the amd 5700 official driver page download the latest complete package
which should be 21.1.1, once you download extract the whole package to a folder on your desktop
once this is done go into the folder, click on packages then drivers then audio then hdmi
then you will see a folder named WT64A Click on it
then open the AtihdWT6.inf scroll to this line
HKR,PowerSettings,PerformanceIdleTime,1,0A,00,00,00
then change it to this and save it, if it gives you a need administration rights just save it on the desktop then replace it in the folder
HKR,PowerSettings,PerformanceIdleTime,1,00,00,00,00
after this install the whole pack from setup like usual
reboot the computer and test it out you should not be experiencing any audio cutouts anymore
let me know how it works for you.