Outer Limits 4x4 Board

My GQ developed a clacky sound in the back after my last camping trip. I traced it back to the small back door. If I sit inside and pull on the door handle repeatedly I can replicate the annoying sound as the small door has some play in it.

I tried adjusting the locking bar (on the big door) to sit further fwd/in and I found that it was already on the innermost position.

Has anyone noticed this problem before? How can it be fixed?

Check for wear on the round rubber striker on the catch at the top of the big door.
I replaced mine due to the big door not sitting in the right place when the small door shuts against it. It seemed to fix the problem.
Also check the rods inside the door that operate the lock.
These have foam dampers on them which fall off.

i had the same problem try taking the latch that you tryed to adjust off and turn it around this gives you about 5mm more adjustment cheers