[jimcol]

When I had an issue with my frig I conferred with Dave Forest of RV Cooling Warehouse. He is a wealth of information on RV refrigerators. We got acquainted with him when I bought a replacement coil unit from him when the OEM unit leaked. Here are his instructions:
Use a hair dryer to go around and around gasket or just in the area you found it not sealing, the heated vinyl gasket is allowed to soften making the gasket flexible enough for the magnet inside the gasket to flex vinyl, close the door so the magnet flexing the gasket will make contact with the metal frame allow to cool. This will be flexed and cooled in a sealed position. You can also use a little bit of Vaseline in the area you are checking, once the door closed and reopened the point the gasket did not seal will show by the Vaseline was not disturbed on the refrigerator metal surface.

This method fixed my problem.