well to be honest don't know much about your Winegard in-motion minimax.Did a quick search and it states that it toggles between 110/119/129 it also states that it will work with eastern arc.So in theory it should be getting 129.The 322 should see all 3 sats.All that leads me to believe that something is blocking 129.
Winegard RoadTrip MiniMax Satellite TV Antenna looking at the pdf near the bottom of the page it says This model is PRESET for DIRECTV receivers. If you have a DISH Network or BELL TV receiver, you must change
the numbered switches.
I've seen 322's check switch on a 1k2 just the way the op describes in the 1st post. That makes me believe it is at least recognizing 129 because it is toggling automatically between all 3 sats during the check switch. From the point dish screen she should be able to at least see signal on tp21 on 129. That would would concur whether or not something was actually blocking 129.