Do a search as other people have had this problem and parts are available from Dometic. I think there is a plastic piece and spring that is needed.
Have you done this, search your model number.I am having the same problem, but I can't see any damage plastic part. Where it is located exactly?
Normally it is a plastic part that breaks. No way to adjust the spring. Had this happen to mine on our trip to Alaska. The part does not cost much an I carry a spare left and right. Go to the dometic website and download the parts break down to order the part. When you remove the door and compare the left and right hinge assy you will see which part is broken.