TJ Rubicon locker won't fully engage

Don't pull it apart yet

While it's in there engage the pump with the cover open and have someone spin the wheel and watch the locker to see if there is any wobble of the engagement plate. I do wonder if something is blocking the engagement from happening 100%.

I'd also listen for noises as with the fluid out it should be much easier to see if you have a problem.
 
There is a popping noise when it slips out. The engagement plate gets pushed out.
 
Sorry, I did not think it would have offended you by asking again if the carrier had been removed/replaced recently. Doing that could cause a problem with the sensor that could hang the locker actuator up.
Regear was over 5years ago. Last time the rear carrier was out.