Door lock conundrum

[full foot notch]

So I'm doing all the little things on my truck to make it 100% and general upkeep , and one of the items is the door locks and making sure they operate properly. When I bought the truck the driver side and passenger side were finicky with locking them. They unlock fine by key but occasionally the lock wouldn't want to go all the way down unless I put some pressure on the key and then it would go down slowly

I figured that I would look at the passenger side and see if anything needed to be lubed or if it needed to be repaired. Took off the door panel and all seemed well by moving the key in the cylinder for lock and unlock and the lock stem up and down to do the same with the door open. All seemed perfect, got everything back together, tried it all again, all seemed gravy, I'm in the home stretch right ? Nope. When I lock the door and then try to close it it unlocks itself. So I thought hmm that's weird. Locked it both via key and seperately with the lock stem and get same result. Thinking maybe it some anti lock out feature, maybe you need to hold in the pushbutton on the door while closing. Nope that didn't work.

my next thought was to do further process of elimination and see if it's the lock or lock stem and it seems that when I closed the unlock door and try to lock it with the key, it does not want to lock even though it makes the motion of turning towards the lock and all, until you test the pushbutton and then it opens like normal.

I open the door and look at the latch mechanism on the door and I can see a tiny part moving when I move the key or lock stem to lock and unlock and nothing seems to be binding or blocked.

So that's where I'm at for what do I try next or what do I look at next or is there something I need to adjust and don't know about since it's my first 67-72.