[Renate]

Originally Posted by Pentam

I can see a "super" partition on the device.

The super partition is a bit of a stinker.
Normally you write that in recovery or in fastbootd (inside recovery).
I haven't delved into that much.

Have you been switching partitions A/B?
That might fix you, but it also might make things worse.
You really need to get a somewhat functioning normal system so that you can do an update from there.