Rear lift gate alarm.
 

In thinking back this may be happening for years. Just did not occurred to me or just though it was a fluke.

But this is what is happening. If I use my remote key to just to open the back gate, I can unlock and open the back gate not problem. But after a minute I hear a click. The same click I hear as if I did not open any doors and the car is re-locking. Now if I jump in the trunk or put heavy cargo in the truck the alarm will go off. To me this means the car re-armed with the car not knowing the back gate is open. Now it will not rearm or set off alarm if I unlock (not necessary open) any other doors if I open the back gate. Now normally I will not notice any issues because it takes less than 1 minute to load or unload stuff in the truck. I only notice this if I am loading or unload stuff for longer then a minute.

1. First is this normal?
2. If this is not normal. I am thinking there is a lose wire at the rear gate latch or handle that is not telling the car the gate is open and rearm. In another words wire to a sensor is lose or something.
3. Anyone has dissemble instructions or diagrams to get to the latch or sensor?

thanks in advance.