DirecTv connection to Winegard RoadTrip Mission satellite dish

I am not getting all of my channels and am getting the 771 error code on the channels I am not getting

I have a Winegard Roadtrip Mission dish with a SWM8 and HR24 receiver

That is an SD-only for DirecTV as isn't compatible with their MPEG-4/HD. It is both SD and HD for Dish.

DirecTV going forward needs either a slimline SWM dish on a tripod/sled mount or the Winegard Trav'ler if you want the auto-acquire capability.

Less and less areas can use the old domes as DirecTV has been shutting down their old MPEG-2/SD-only feeds. As the shutdown is not completed (impressive as started in 2019 as planned) mobile dish/dome sellers are getting rid of old stock as much as they can while there are techincaly some use for them.