I had the same problem as @MisterM23 and @MetCam. I managed to "fix" it by changing the 'LockStatus' in the Vehicle Keys XML file:
From
<LockStatus>Locked</LockStatus>
To
<LockStatus>LockedButCanBeBrokenInto</LockStatus>
Not sure if this is caused by another plugin I have installed, or an update, but I thought I'd point it out in the hopes of helping others.
Otherwise a great plugin, thanks!