Found It.... one inserter was missing a green wire. This is why I could not find answers when googling! Knew it was something stupid. 3 hrs later. LOL

Hey All, the only references I have been able to find on this question are either not answered or OLD. Hoping y'all can help me out before my brain implodes.

Built a simple circuit - 48 chests connected to each other [green wire] and to the input of an arithmetic combinator. [Iron / -48]. Output ...