Software quality continues to be a problem at Apple:
Peter Kirn said:Apple’s latest Macs have a serious audio glitching bug
... all T2-based Macs, that is all Mac models from the 2018 generation, are evidently unusable with USB 2.0 audio interfaces, irrespective of vendor. Audio interfaces using FireWire or Thunderbolt are reportedly unaffected by this particular bug, but USB 2.0 is for the moment the most popular bus for audio devices, so nearly all owners of the new machines are encountering the issue. (There are also some reports that USB3 devices are unaffected, but I can’t confirm that.)
This of course has led some users to simply buy a new Thunderbolt 3 audio interface. But this situation is unacceptable – plenty of standard, inexpensive PCs have no such issues with Thunderbolt and USB audio hardware. Apple has shipped their entire computer line with buggy firmware that renders those machines unusable for the majority of people working with sound (so music, video, and audio production), and have lagged in finding a solution for months after shipping these expensive machines.