K-1 ordinary income change not affecting 1040 refund

I've been using Turbotax for over 24 years. Something new has happened. When finalizing our 1120S, I realized the Ordinary Income on the generated K-1 to me would be reduced by about $2800. When making the adjustment in TurboTax Premier 1040, I was expecting a larger refund. The NY State refund increased, but not the Federal. This made no sense, unless there has been an IRS law change, or a defect in the Turbotax program. Just as a test, I started changing the K-1 'Ordinary income' on the 1040. I added $3,000, then $6,000 to the ordinary income on the K-1. No change in the Federal refund, only the NY refund. Not until I added $8,000 did the refund change downward.  Does anyone know why this would be? TIA!!!