I've had a lot of problems with USB DACs as well. I frequently find that audio degrades into a kind of stuttering or static that doesn't go away until a reboot. I've experienced this with multiple DACs (Aune, Centrance, O2, and Presonus) on multiple machines (iMac 5K, 16" MacBook Pro, and hackintosh). I feel like it's worse in recent versions of macOS (say, High Sierra and later), but it's intermittent, so it's hard to say.