side car works on my MacBook Pro (2017 Touch Bar) but not on my Mac Pro. I get the message "Unable to Connect to iPad. A miscellaneous error occurred (-501)". My iPad Pro then switches to the Lock Screen, so they are talking, and both can see each other. I can find nothing anywhere that relates to error -501 apart from some reference to a string array. any one got any ideas?
this has happened from. Catalina right through to Big Sur.