So...I have 2 older iMacs that both have 22 installed. Probably 22.0....maybe 1 or 2? Not sure. In any case, my update process is apt update, apt dist-upgrade. On both of these iMacs, after doing apt dist-upgrade, both rebooted to a login console. I had to do an apt install ubuntu-desktop to get back to Xwindows and gdm. Just an FYI really.