TinyFPGA BX - Ubuntu freezes for up to a minute when connecting USB


I’m just getting started with TinyFPGA BX. I’m using an Ubuntu 20.04 guest OS running in Parallels Desktop 16.1.1 on Mac OS 10.15.7.

I went through the tutorial and successfully built and uploaded the blink project.

The problem I’m having is that every time I connect the TinyFPGA BX via USB to Ubuntu, including when I press the reset button on the device, the Ubuntu guest OS will freeze for up to a minute or more. The OS is completely unusable during this time; I put a clock on screen and it redraws maybe once every 10 seconds during the freeze period.

Mac OS, Parallels and Ubuntu are all at the latest versions (I was having the same issue with older version of each of these; updating to the latest did not make a difference.)

I’d appreciate suggestions on what to try, or how to even go about troubleshooting. Has anyone seen this type of behavior and if so what was the context and the fix? Thanks,