Electrical

your connections are borderline disconnected , clean the battery posts and inspect for loose connections

Little run down on battery stuff? Some vehicles will protect starting integrity by disabling various components that use power when low voltage is detected. This is a feature usually found on high end vehicles. Does this truck have a similar feature, not sure. Replace the battery if its old 3.5+ years. But yes if your connection is loose you could have similar results.

It could be in the security interlock system. Nightmare. I have a 2007 Suburban 6.0. I have a good tech at the dealership I use. You are resetting the security module when you disconnect the battery. I have a Snap-On Scanner but I still need the dealer to help. Eventually one day it just wouldn't turn over. Nothing. Had to have it towed to the dealer. Changed the key interlock then it would give codes. Then changed the security module. It works but once in a while you see the clock reset to 12:00 and it'e something in the wiring now. Check the other things in the other post first. Just a heads up on this issue. Anyone else with security problems?