I used to own a Teardrop American. It also had problematic doors. The ABS plastic gradually straightens out from the weight
and other factors, and the body of the trailer also slumps with age. I fixed them by making a template of the curvature of the trailer door openings. I then used the template when I ratcheted the doors with straps to match the curvature of the openings. On a day when the temperature was in the 90's I put the straps around the door and very slowly matched the curve. Remove the doors first, when you get the proper curve you will need to reinforce the sides of the doors so they don't revert back to the prior (bad) curve. I used strips of metal cut to the new curvature, a glue from Home Depot made for ABS plastic (a type of Gorilla glue) and sheet metal screws. Let the glue cure before you remove the straps. This worked for me and may work for you too.