The simplest, fastest, easiest way to handle this is to apply plastic wrap from one door jamb to the opposite door jamb so that it sticks out a little on both sides when the door is locked in place for travel. Whatever is in the door pocket will stay there. My aunt taught me that 30 years ago. She devised this method when the retainer bar broke on hers. Couldn't hurt to try it out. Cheap fix.
__________________
"Walk softly...
and carry a lot of tools!"
2016 Ford F250 Super Duty Crew Cab, 4x4
2021 Palomino Puma 27RLSS