Joe, your trailer has a Lippert frame and they have had problems with welds for some time now, so check them out good. Spring hingers and hitch plates, seam to have a few weak welds.
Doug
Been there, Dun that WD.
The 2X 1/8" base plates on the (Lippert) Gooseneck, where the Coach (Keystone) mounts... had 16 spot welds, of which 12.. didn't have any penetration.
The Coach began to sag, on the frame. I caught it early. I cut the 1/8" soft steel off, replaced it with 6X 5/16 thick tempered iron straps, ran a continuous bead weld, with 4, "Rosettes" on the overlaps, on each side. That Fixed That.
Hangers, rewelded. Springs and Hinges... changed to DEXTER, all 'round.
Hitch plate is now.. AirBorn, Air bag w/Shock absorber.
Sorry Crumm.