RStudio freezing since upgrade to macOS Catalina

No dire disasters so far, and I'm able to save edits. Did you have this problem before 3.6.3, which only came out on 2020-03-29? I now think it may be the non-sandboxed version of 3.6.3 that's the trouble.

oh, and btw, welcome!

Please see the FAQ: What's a reproducible example (`reprex`) and how do I do one? Using a reprex, complete with representative data will attract quicker and more answers. This one, of course, doesn't require one.