I am on Mac OS Catalina (10.15.7 (19H114)).
I notice mostly when running tests, IDE tries to compile, write classes, etc. It seems to 'hang' on the "writing classes" part. Most of the time (90% >) the IDE responds fine (so no UI is blocking?). Sometimes it does block UI (I get the OS spinning wheel).
There is no feedback on to why/where it hangs.
Rolling back to 2020.3.1 seems to have resolved it (for now).