Just dropping this here in case, anyone else bumps into it. I loaded AI and Sharpen as plugins in PS2020 and got the AutoUpdate prompt.
I closed the image I was working on and the update appeared to install fine. However, when I launched the plug-in again, all the buttons worked and nothing happened. I can only guess a file was still open and the installer didn’t error.
Anyway, I uninstalled and re-installed them and everything is good again. Takeaway for me is to close PS before letting the updater run.