For the first time I tried the Synscan driver for my AZ-EQ6 in Alt-Az mode. After the initial alignment procedure with the HC I was able to connect via the HC. I could execute Gotos, but I could not sync the Mount to the correct position. I tried to sync via the Ekos alignment module and also manually in the indi control panel by entering the data from the solver solution, but the new coordinates would not be accepted.
Thereafter ekos/kstars crashed and it kept crashing every time I tried to reconnect to the mount. The GDB log is attached. Any advice ?

Did you put the HC in PC Connect Mode?

My mount is HEQ-5. I faced many troubles in using ekos with HC. Even when I set the HC in PC pass-through mode, I used to get rouge signals that put my mount position in KStars below the horizon. The best way I cab use HEQ5 with KSTARS / INDI is through the EQDIR cable, and not using the HC at all. I only use it at the beginning for polar alignment (as Polaris is blocked for me), and then park the scope, turn it off, remove the HC, connect EQDir cable and then start Kstars/Indi connection

more information about what I went through is on this thread:
www.indilib.org/forum/ekos/7635-lost-tracking-guiding.html

No, I did not put the HC in PC direct mode. I wanted to use the mount in Alt-Az mode. I only use the eqmod direct connection for equatorial mode.
When connecting with the Synscan driver, you first have to do the alignment procedure via HC, than you should be able to connect to the HC without going in PC direct mode. The PC direct mode will bypass the HC. One can do this as an alternative to the eqmod direct connection for eqmod.
Just wonder, why I can´t sync.