Well, believe it or not, that was enough of a push in the right direction to find the problem. While inspecting the hinges I popped off the previously unseen flashing that covers the outdoor screws mounting the door to the frame. Both of the top two screws were considerably loose, 1/8" out ... effectively allowing the door to bend at this hinge. (screws shown in attached)
Now it is closing nice and smooth again.
Thank you!
Now it is closing nice and smooth again.
Thank you!