Not to revive a dead thread, but I was searching around for clues to solving an issue I’m hoping is very similar. I have no other peripherals connected to my MacBook Pro M1 Pro (and I tried with another MacBook Pro Intel i7), only the DigiRig which is connected with a short DigiRig USB C to USB C cable and connected to the DATA port on my Kenwood TM-V71A, listening to audio on the B channel. After almost exactly 4 minutes, I start hearing cracking and clicking and by about 10 minutes passed the audio is so unreadable that I have to unplug the DigiRig and plug it back in which appears to be the only way to solve the issue. I’ve also tried with another USB C to USB C cable of my own with several ferrite beads on it to no avail.
I can also confirm that every Windows machine I’ve tried a DigiRig on works flawlessly once configured as I’ve been running an iGate on Windows 10 for months with no issue. It seems to only affect macOS.
Edit: I managed to get a recording on macOS of APRS traffic heard by my radio which demonstrates the issue. There is a large silence between heard packets from 0:15 up to ~2:00, but after that there is a very clear packet signal heard at 2:24, 2:42-2:47 has some clicking following the packets, 3:23-3:27 has some crackling, 3:35-3:39 has some trailing crackling that you can hear is getting progressively worse. Almost every 0:30 there is a packet after 2:00 so play around with the file and see if there is any hints in there.