2011 Sierra 1500 vortec 5.3L with the tick. Whats the issue?

What is your question?

Removed valve covers and check the push rods, rocker arms, rockers, and everything has full range of motion and moving normally w/ no play in rockers. This rules out the lifters or having a collapsed lifter. It only ticks after warming up (10-15 min after cold start up) what else could be the issue? My car has 102000 miles. My car has an automatic transmission.

What makes this problem better or worse?

stars after 10-15 min cold start

How long has your 2011 GMC Sierra 1500 had this problem?

a few weeks