66 cuda door stuck help

Remove door handle and look for worn spot where thumb push activates linkage that works door latch. You may just need to weld a small piece of sheet metal to shim it out to restore full motion of linkage. In other words; mechanism is worn enough so that when push button is fully depressed the linkage can’t fully retract rod to release the door latch. I had this same problem on my ’67 Dart.