I just went through having the same exact issue with my RX 5600 XT.
Running my PC through HDMI to Yamaha Receiver passthrough into 55" 5K TV .
The only thing that fixed it for me was to use the AMD Cleanup Utility to clean out all the drivers, reboot, and use Windows Update (Windows 10) to install the drivers from Microsoft.
Audio stuttering is now resolved.
It's a shame that AMD can't even come up with consistent drivers for their cards,