[randy500]

The latch pawl and the lock pawl act upon the latch/lock cylinder slightly offset, not in the exact same place.
The latch pawl itself wears and so does the latch lock cylinder which causes the latch lock cylinder to rotate to where the lock pawl crashes into the tooth it’s trying to engage to lock.
You can feel the lock pawl crashing into the outer tooth by simulating door latche pressure on the latch with your finger while trying to engage the lock either with the key or the knob.
The center pin also wears and causes misalignment of the latch/lock cylinder. The center pin should be fixed and not move or rotate but most used latches the pin is loose and rotates.

So here is the quick fix, remove the latch from the door and grind some clearance into the lock pawl contact surface with a die grinder or dremel...or replace the latch.
I have a truck here that I acquired with a repro latch and it works fine and seems to be of good quality, brand unknown.
Grind the flat surface to the right of the “2” to prevent the lock pawl from crashing into the latch/lock cylinder tooth when latched. Grind enough so the lock pawl clears the tooth without contact.

Using your finger on the latching teeth to simulate latched door pressure you should not be able to feel the engagement of the lock, if you can feel the engagement there is not enough lock pawl clearance.