[twindman]

I have had this exact issue since new. Also a 2013 Monty (mountaineer). I am almost positive the opening is too small. There is not enough space at the top and it presses upward almost on the seal. I did notice they apparently have double seals all around now, so it is still sealed. Am pretty sure my 2006 did not have double seals.
OH, my dealer looked at it and agreed and could not adjust the slide enough to help.