[LNP]

Another thing to check since you have to shoulder the door to open it is the door hinges. Partially open the door then lift upward with it. See if theres movement with the door seperate of the truck itself. A bad door hinge can make the door drag along the latch piece attached to the cab. Opening the door from the outside you can easily be pulling up as you pull towards yourself when opening the door and not notice a drag. As stated you do need a inside door handle but sounds like you got something else going on as well.