Jetta door latches when locked, but otherwise won't close.

Seems to be a different issue than I am finding in the forums - over the winter a couple of times the door was difficult to open and I had to pull the inside handle harder/with more tension than usual, and then it would not latch again for a little while - either until the car warmed up or I drove a bit and I'm guessing something jiggled loose and it would latch. This would be intermittent, and seemed better on warmer days. Now it's warm all the time and the issue is more consistent - mostly not latching closed unless I hold the door shut and lock it. When I do that it shuts, stays closed and opens normally - but usually won't latch again until I lock it (although sometimes with no rhyme or reason it will latch without my needing to lock it first). I suspect it is mechanical vs electrical since the latch works when locked by either the door button or the fob... is this something you've run into before?