after upgrade, unable to boot

[fabian]

That's definitely, provably not true. How do I know? Because 1 of my nodes, which I never fully setup & doesn't currently do anything is still on 8.2.2 after multiple apt upgrade processes while the other 2 have updated ONLY after a dist-upgrade on 1 & full-upgrade on the other

then you either
- misconfigured your repositories and don't get PVE updates at all on that system
- are exactly in the bad situation I outlined above (stuck on outdated versions because using the wrong upgrade command), but just lucky that it doesn't break (or you haven't noticed what got broken)