Crimsafe Triple Lock Door Mechanism Adjustment

Has anyone else experienced the same problem I am having with my Crimsafe front door lock mechanism? It used to work fine but gradually the upper claw lock started to slightly catch on the other door (it is a double doorset) and now it is sometimes quite a battle to get out using only the little snib lock lever. This seems to be getting worse. Using the key from outside is usually OK. All three parts of the lock mechanism appear to operate together but the upper and lower claw locks appear linked and although the upper one catches, the lower one seems fine. I wondered if they are linked by some arrangement that is adjustable and this may be a simple task to remedy. I didnt want to start taking it apart until I knew more about what is involved.

Any ideas anyone? Thanks for anything you can suggest...

Have exactly the same problem. Have had the locksmith out twice now. He reckons they're just crap locks. I've found you need to keep them well lubricated. Silicon lube seems best.