so you don't experience the problem with the ppa version? There is no 3.6.3 version on the ppa repo, afaik. Which version do you have currently installed? Is it finding the right libindi library version?
Looks like indeed I had some leftover stuff from the nightly PPA. I ran ppa-purge once again and it removed some indi stuff. Now KStars it at least starting.
Now I also remembered why I switched to the Snap version at some point: with the version installed from PPA, the Optical trains menu does not work at all.. but since this is getting pretty far from the original topic, I'll create a new topic for that issue.