macOS Catalina beachball appears when I use TextEdit or Preview apps
Hi I did some more Google searching, and so the answer for this bug I was facing is to Disable the "Dropbox Finder Extensions" in the "Extensions" section in System Preference. 

It seems the Finder features of Dropbox (like green dot next to filename in finder etc.) was causing beachballs in using TextEdit &amp; Preview. Now it's been fixed for me.

Since it's a bug, I hope Dropbox &amp; Apple will fix it.