Please report this issue in feedback, this is one of the few that Apple has reached back out to me on. If they do, they will provide a method to log with ktrace and a few other things so they can look into it. Based on this it is definitely a known issue. If you want a guaranteed way to trigger the crackling and popping, run a VM on the system. Especially a mac VM using the apple virtualization since that is 100% apple, but any should suffice. Or obviously a high cpu/gpu load for a while. Then exit the VM, just running it will start the problem and make it highly likely any cpu use will cause lots of popping, until you reboot. My guess is it is a driver that causes a buffer to go nuts, as killing everything related to sound at a user level does not work, so it has to be something kernel level or something similar. Pay attention to the popping, many times it will be audio going out of sync and back into sync in time. Very obvious with youtube videos where it will glitch and sound like someone said something twice. I was also asked to test the noise with playing "silent" audio. It never happens with silent which really makes me sure it is a buffer repeating/desync/catchup issue as a silent audio would not produce anything that would generate a desync, or you wouldn't notice it anyway. BTW the teams driver may be AN issue, but it is not the cause. It is easy to generate with or without it installed, especially using the VM method above.

Thank you all! Great discussion and apple needs to read this. They definitely changed something. For 20.04 with zfs, and stock samba, the proper answer appears to be: vfs objects = aclxattr catia fruit streamsxattr fruit:nfs_aces = no inherit permissions = yes My concern about the above though, inherit permissions, does this mean apple can no longer control the permissions in the directory? I worry this will be an issue, the change something, it doesn't match, so apple just thinks the file system is corrupt and time machine goes haywire. Also, I put it in zfsacl but that did not work for me. I am sharing a folder from a zfs mounted file system, not a zfs mount itself. There might be something with the configuration of that vfs item required to make it work.