Wanted to close this up for anyone reading in the future. Before this truck, I had a 2004 2500HD with over 400,000 on it and I was constantly working on something somewhere. It was always nice to be able to browse the internet and find an answer somewhere.
I tried replacing the blower motor with a new one and the issue persisted. Returned that blower motor and was perplexed by the issue so I decided to run the truck into the dealer today. Dealer diagnosed it as the HVAC Controller (the knobs and buttons for the A/C). Dealer advised that the part was on back order and couldn’t tell me how long it would take to get one but that it would be around $500 with parts and labor whenever they did.
Fast forward to tonight, ordered one while eating dinner and it should be in in a few days, for less that $130. Seems very easy to replace. Just have to pull a trim piece off, remove a few 7mm bolts and pop the old one out and pop the new one in.