Hello All,
Today I tried the Trial version of JRiver Media Center 27 on my iMac running Catalina. I was able to rip 5 CD's as .m4a files until the 6th CD would not read or rip. Yet, without reinserting the CD it ripped perfectly when using Apple Music. Then, when I played songs from the Media Center there was initially no sound, yet, Apple Music played fine. I changed my output in Apple Sys Pref to internal and then back to my external Dac and there was sound. In standard view MC27 unconventionally takes up my entire screen, it is difficult to resize and move the app window. It jumps all over the place and resizes itself. When I hit pause the window moved so far to the left the controls were hidden. When I tried to move the window it dissappeared completely. At some point a message appeared asking permission to read my screen. Then I changed the view to mini and back to standard and a normal sized window appeared. So, I played on a song, no sound, fiddling with Apple Sys Pref's Sound had no effect. Finally, I uninstalled JRiver Media Center 27.
Thanks for listening, I'll check back for responses...