stubblejumperHi
Hi
I have try a few time to zero SH follow instruction from iOptron manual, it shows 90/180 and set to zero, and apply to mount.
And after above, I launch ASIAIR app, the RA/DEC is not show zeros, but some related data(could be related to your ALT), after that I point SH to Sun by ASIAIR App(I tested it indoor, just simulate), the mound slew to Sun direction.