The two screws shown below hold the bag locks to the bags. They are known to come loose. They should be removed, coated with blue thread lock and re-installed to prevent them from working loose. The screws are Torx T10 security screws. You can get the appropriate screw driver at Harbor Freights.
One other issue I was having with one of my bags was squeaking when the outer shell was closed. I was able to determine this was caused by excess plastic in the rectangular holes in the inner shell where the steel plates of the outer shell slide into. I used a box knife to shave off this excess plastic and the squeaking stopped!