Yep, slimjim.
Easiest way to fix that is to remove the doors, and fully dismantle.
Drill small holes along the inside of the top of the door, below where the interior panel goes.
Fold a thin piece of steel on a metal brake, most of the length of the door.
Put that inside, so the folded part covers the holes from the inside, and tack weld it the length of the door through the holes (plug welds).
Reassemble door.
Now, any slim jims shoved in, will flex away from the door's internal mechanisms.