Mike - Something to try with whatever gasket you use next. Once everything is in place, adhesive/sealant dried, etc., take a piece of chalk and rub over the seal surface that should contact the door underside sealing area. Then close the door (fully latched position) and reopen to check for chalk transfer to the underside of the door sealing surface. If you don't have chalk transfer all around the perimeter of the door sealing surface it still not sealed.
You should be able to see where it's not touching (no chalk transfer) and use that as food for thought on how to correct the problem (thicker gasket, more pull down on the operating latch setting, etc.). Best of luck and please let us know how things turn out.
