On my cougar ftd Im having problems with lathes. Some times the key works an sometimes they act like its the wrong key. Im not talking days apart but mins. They will lock every time but then they wont unlock jus mins later?? I had one raised an stuck key in an it worked , shut it & turned to lock an it immediately wouldnt unlock. I had to pry 2 open Saturday morning after spending 30 min on them. ?? Any ideas?