Ok I just tested the same setup with kstars 3.6.8 and the ASI294MCPro camera works fine.
It starts on 16 bit and stays there.

I would say there is some sort of bug in the binary version of kstars 3.6.9 that I have.
It was installed from the ppa
deb ppa.launchpad.net/mutlaqja/ppa/ubuntu jammy main
so not a nightly build, but the stable release.
Client x64 Linux mint 21.2 (ubuntu 22.04 base)
Server arm64 Armbian (ubuntu 22.04 base).
kstars runs on the client so not an issue with the server.