Like before with 10.3.1, the IDE just freeze when trying to debug a 64 bit macOS app. I have to terminate the IDE.
I have so far no way to debug anything on macOS since the Catalina update.
I checked for any debugger patch from Embarcadero, but there is none for this issue.
I compile and deploy it, all is fine, I can also run it on the mac without issue, but when I hit F9 to run it with debugger, the IDE just freeze and the app doe snot start on the mac.
I use Delphi 10.3.3 and build 64 bit macOS apps on Catalina (10.15.2). I can debug my app, so it is not a general problem.
However, it might be caused by the XCode Command line tools not being installed, or that you need to grant the debugger process access with your password on the Mac. I have experienced that the dialog to grant access are not always showing up, which blocks the debug process and therefore also Delphi, as it waits for it. Try to restart your Mac, and to start XCode before starting paserver.