I don't know what you're referring to by "income entered for ISO exercise and hold." You have no income, for regular taxes, by exercising an ISO and not selling the stock by year end. The "spread" between the exercise cost and the FMV of the stock not sold is an AMT adjustment that goes on Form 6251 and TurboTax makes that adjustment for you.
By any chance did you go through the AMT interview and enter that spread as part of the interview. That would result in a "doubling up" of the adjustment.
That was it! Thank you for figuring that out. I had done the math on my own spreadsheet and added it under AMT adjustment, then also entered the specifics in the other section, so it was showing up as double. It was looking like I owed an extra $8000, which didn't make sense.