When I looked under the plate I found a bogus spring installed. Although it was probably installed to move the door latch strap aft in hopes of being able to latch the door that doesn't work very well because the other end of the latch strap has play in it and won't force the door catch to fully engage.

Remove the cotter pin on the arm being careful not to lose the tiny clevis pin. I taped it onto a card for safe keeping.