There are still a number of clock sync issues with the Zen4 chips. I’ve had issues on 6.4/5/6 with similar sounding audio/video that I’ve been able to somewhat mitigate by getting my amd_pstate settings to stop competing with other power tuning tools. Turn off EVERYTHING you have running dealing with cpufreq management, and just let the kernel amd_pstate do it’s thing. No TLP, no desktop tuning tools, just the upstate.
Also, double check that your memory frequencies aren’t bouncing all over the place, and consider under locking in the BIOS to exactly match the channel freq for CPU/mem.