what's the pi model ? I'm use since 2 (or 3)years a pi (3 and now 4) for controlling mount, camera, focuser, gps, ... without problem. But always through the ethernet connection (with a cpl box). I controlling my mount with Bluetooth.
I noticed with my pi3, that the wifi connection wasn't very speed and is for this reason i didn't used. I suggest you, in the fist time, to test directly with an ethernet cable.