When you say open you mean the locks were still locked but the door was ajar. If the door is still locked then there must be some real flexing of the door jam/trailer frame. with the door closed measure the distance from the door to the jam and then measure the distance the deadbolt extends. It may be you have to make a shim that ensures the dead bolt stays engaged.
Jake my sidekick (yellow Lab) 10/04 - 05/20
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM & El Korah Shrine of Idaho