This has happened in last few days, but has been on the cards a while. In order to lock the doors, the handle has to be pulled up, which engages top/bottom bolts, and 2 claws into the joining door.
Now, pulling the lever up with the doors closed engages all the bits, but the key won't turn fully to lock the door. Every so often (hot and cold weather), the handle has needed a very firm lift to enable the key to turn and engage the lock. But now it won't budge.
The lock will work when the adjoining door is left open, and the locking door is closed, in the frame. So, I assume, the top and bottom bolts are fine - it's the claws that aren't engaging fully. Thing is, I can't see any easy adjustments. All screws are tight with no wobble. Everything is fixed and set into rebated wood. The only thing I can think of would be to enlarge the part where the claw enters the adjoining door - maybe filing some of the material away.
Any other ideas?