This is the Xsession error log message. Consistent in Ubuntu 21.10 and 22.04
kstars: symbol lookup error: kstars: undefined symbol: _ZN7SSolver10Parameters14convertFromMapE4QMapI7QString8QVariantE
I think this means the launcher icon is pointing to the wrong target - but I'm no expert
btw, Indi Web manager app can start the simulators without any issues.
However, recompiling from the github sources fixed the launch issues for me. I have a Celestron device connection issue now, which I haven't investigated.