Hi @Rafu
Looking at your check with and without sudo it found your scanner:
I had the same issue and solved it now - via logsearch and reinstalling the printer.
But I use an HP and could simply call the hp-setup utility.
Can you open another terminal window, start journalctl (like following)
journalctl -f | grep scan
then start xsane? What does it say?
For me it printed something about missing attributes:
simple-scan[12975]: io/hpmud/model.c 532: no tosmart_plus_b210_series attributes found in /usr/share/hplip/data/models/models.dat
Reinstalling helped in my case.
Hope that helps.
Greetings