This seems to happen every other year/MacOS update, when several of my day-to-day go-to software doesn't run properly on the new OS. Hence I never upgrade MacOS until I know it is safe (usually about half a year to one year later). I just upgraded to Catalina yesterday (smooth), and will probably wait with Big Sur another year. If there are enough new goodies in the newly released OS version (which happens quite seldom), I install it on a separate drive, using dual boot.

I realise it is frustrating for you who have already upgraded, and I appreciate the hard work I know the PGMusic developers put it to solve the problems as quickly as possible.

Stay safe and have a really Merry Christmas!