I had that happen on our most recent trip. After raising and lowering the jack several times, I backed my truck up just a tad, and it did the truck. I had looked at the ball and the coupler and took a guess that as the tongue of the trailer was going up, tension at the front of the coupler was increasing i.e. the hitch ball was jamming against the front of the coupler.
It makes me wonder as to how often others have had this happen.
Retired but busier than ever!
2013 Winnebago 2201DS - 6,200 lbs. or so loaded!
2007 Tundra 5.7