My prior was a 30 ft Newmar KS, it had a pocket door between the walk through bath and the living area. There was a pocket door that separated the two. It would sometimes come off the track at the rear roller.
On that unit, it had a metal "V" grove track with a roller assy on either end that fit into the "V". The track had a stop strip above the "V" that was suppose to keep the rollers from lifting out. In all the years we had the unit it lifted out three times.
I was able to lift and using a little force pull it back down into to "V". I can't say what the Excel use as I haven't seen the setup, so not sure this is helpful.
2000 Alpenlite, 29 ft Valhalla - 2014 F350