Welcome to the club, I had the same problem a couple of years ago except it was the left front jack. I went through all the suggested diagnostics and then sent the control board in to be “rebuilt”. They didn't find anything wrong and it still cost me $400.
I removed the offending jack, took the motor to an electric starter repair shop to have new brushes installed. The system still didn't work.
Eventually I had all the jack motors cleaned up with new brushes installed. Still didn't work.
I ended up taking the control board out and replaced it with a GAMA remote control board (<$200). (Gamainc.com) Everything now works but it doesn't have auto level capability.