Yes, it seems. I also tried installing to the hard drive inside Catalina after launching the installer, but after the restart and installation, result was the same. By the way, how did you download the BigSur and Monterey installers? I downloaded using Opencore tool which includes even the updates, non of my previous installers were like this. Maybe it's just me over thinking. I really wonder if I've downloaded the launch version and if it's not going to fail. Anyway I've finally updated Catalina and gonna use it now ^_^ I hope there will be a way for you to update it to make your workflow smoother. Good luck!