Do you have the metal supports that are designed to go into opposite corners after raising the roof? If so, and if you are like me, you always snap them into the same two corner posts, then swap corners and see if that helps. Just guessing that if there is a problem it might sturdy up the roof and help pinpoint a problem, if there is a problem.
I'm just pulling an idea out of my *** but that is what I would do. Good luck....
Trailer: Lifted 228BH, heavy duty springs and Yokohama tires
TV: 2016 GMC Sierra Z71 4x4 CC, SLT
Spare TV: Two Alaskan Malamutes
Living somewhere in ID; previously lived in Moab UT; previous to that, don't ask!