It seems to have something to do with privileges. It didn't connect on new raspberry either but log directed me into that direction/ Didn't help as I already had access but when I run kstars as admin the focuser connects and works perfectly. I will investigate further; later.
funny, now it started working under user too, just complains about privileges to config file which is a minor problem.
Discovered other issue with Odroid XU4 - Telescope simulator after hitting "Connect" crashes Kstars. Doesn't happen anywhere else and build is same on RPI and Odroid. I use external Lin guider but on Odroid I can use other slower guide camera as there is enough computing power compared to RPi3 and for that I need to tell indi parameters of telescopes.