First: 1.) Searched, I don't believe this to be a bracket issue, but just i case I'm going to remove it and shift it by hand next time I have an opportunity.
2.) No body lift, however I do have a 4.5" RE lift which the previous owner installed.
I'm able to get into 2WD hi, 4wd hi, N, 4wd L. At no time does it pop out of gear.
Everything works fine with the exception of 4WD low. Putting it into 4WD low, it seems to engage fine, I'm able to see "4wd" illuminate on the console, however once it's in gear and I give it gas the problem seems to occur. Giving it gas it doesn't move until you give a good amount of throttle in excess of 2500rpm. It feels as if you have to rev it to a certain point until it grabs.
I tried taking video, but unfortunately video doesn't illustrate the problem very clearly.