I *think* that since applying the 13.3 update, I'm seeing USB throughput issues, particularly with an USB2 device from Vector (VN1630). I keep getting errors where it's unable to pull data from that device fast enough to clear it's buffers and prevent dropping messages. I don't recall this happening before applying the 13.3 update last week. On a whim, I downloaded VMWare Fusion 13 and imported the same VM into that (and replaced Parallels Tools with VMWare Tools), and VMWare doesn't exhibit this issue at all. USB transfers seem perfectly stable. I recall Parallels had massive USB issues in v17.1.x, I wonder if these aren't fully resolved yet?
What's more, turning off the `Enable USB 3.1` option in Parallels seems to make the dropped frames/latency issue go away. It seems USB 3.1 support is still buggy in Parallels.
Personally I'm having lots of graphics issues in coherence mode since updating. There are reports all over the web about what looks to be a whole bunch of minor issues with 13.3. I'm going to use my backup and return to 13.2 until Apple figures out what they are doing.
