Guten Morgen! I’m also one of the „lucky” C2 users, just installed Whisperfish (WF) and linked the C2 as second device. I did not encounter any issues. @jauri… perhaps you could try completly removing WF and again with a fresh install of WF?
Edit: Pls check also that you deleted at least the db and storage folder under /.local/share/be.rudbos/habour-whisperfish