A search of the dedicated AutoCAD for MAC forum came up with many solutions, here is the most common fix https://forums.autodesk.com/t5/autocad-for-mac-forum/autocad-for-mac-2019-support-for-macos-catalina...

AutoCAD fort MAC forum is over here for your future queries https://forums.autodesk.com/t5/autocad-for-mac/ct-p/4051

HTH