The rear access door on my Trailblazer will not latch when I close it. Help. on 2002 Chevrolet Trailblazer

I am able to move the latch mechanism manually, open and closed when the door is open - when I close the door the latch does not catch and hold the door closed. When I use the automatic lock I can hear the mechanism operating and see the lock arm engage but still the latch mechanism does not move and I repeat, it is not FROZEN or SEIZED. Any advice would be much appreciated.

Asked by for the 2002 Chevrolet Trailblazer
When you move the latch in the door, will it LOCK into the closed position, then you have to push 'open' to release the latch again? If it locks when you move it manually, then the STRICKER needs adjusting. That is the part the latch latches on to. I repeat will it LOCK in the closed position whith the door open?
1 more answer
look at the locking mechanism on the door pull the handle like you trying to open the door theres a little latch on your door locking machanism that you can pull back sometimes youll need a screw driver but it will only work if your hold the door handle as if you were trying to open the door