The clips on my 15 were replaced the day I pick the bike up new. And always felt them lock into position. After my first washing of the bike last fall I found out that some water had gotten inside the bag, I always take the bags off, and the water got through the pin mounting holes.
Anyway the liners were wet so I removed them to let them dry in the sunshine.
Yesterday while I was checking the bag retainer pins before going for a ride like I usually do,
One didn't feel like it was going over center to lock in position, found the problem to be the liner was getting pinched between the pins washer and the bag.
I had been pulling the liner away each time before when installing the pins, and the dealer had just replace the rear tire do to the nail that it had in it.
This may be happening on other bikes and why this is a long responce, I going to reposition the liners today to try to get the holes more centered with the pins.