How do I tell what year my door is??

Never needed to adjust it, always latches fine but doesn’t like to lock, very temperamental about the position on the inner door release as to if and when it will lock at all manually by hand, but only in the fully latched position so figured that to be a mechanism failure. Especially since the inner handle will not unlock the door automatically. The driver side has none of those issues, works great, and is original to the car as far as I can tell.

Everything wears over time, that means occasionally you might need to adjust something.

What you're describing doesn't sound like a latch failure at all, it sounds more like you've got play or binding in the rods and mechanisms.