Leaking outdoor kitchen door

I have noticed that I have water stains in the plastic channel on the outdoor kitchen door. The stains are in the left hand lower corner and the metal latches in the frame are rusty. It looks like water builds up enough and rolls over the channel and into the TT. I store the camper with the front raised on a slight hill.The left corner appears to be out of square a little bit compared to the right corner when closed even when level.

How can I tighten this door to stop leakage?

2012 Primetime 318BHS Touring