Leer 100xq won't lock

Maybe one of you can help figure out my issue.. I bought the wire kit that allows me to lock the shell's door when I lock the truck and it has worked rather well for the most part. Recently tho I have been able to get into my shell/cap when it is locked. The Leer 100xq has a twist style open/close and I am able to still make a quarter twist (when locked) and it pops the door open.

Anyone know how to make this not happen?


Not my truck - just the best image of the shell's main door that I could find online:

 

My thoughts:
When you turn the knob, a wire pulls the latches towards the center.
Either that wire is too short, not allowing the latches to fully retract
Or maybe the latches on each side just needs lubricating, maybe they're not fully latching into place.
Maybe the knob needs lubricating, maybe it's not fulling rotating.

Here's an idea:
Get a helper.
Go INSIDE the bed, with a flashlight
Ask the helper to close the door. Watch the latches close. Watch the knob turn.
You can watch this happen from the inside.

Or maybe it's a bad knob. If you can twist it too far when it's locked, the lock might be defective.
Maybe take it to a locksmith.

 

Thanks for the reply, I had a friend sit in the bed while I turned the handle, I'll try to lubricate it tho next good idea!

I did upgrade the pistons to a higher pound rate which I'm wondering if maybe that is the cause of it all