EDIT- It turns out the error is due to a refi I did in 2020, it is a well known bug that TurboTax doesn't handle mortgage balances very well. Instead of recognizing you only had 1 mortgage at any given time during the year, it combines the old and new lender amounts. If the total is then over $750,000, it caps your mortgage interest deduction.
The worst part of the bug is that the program never actually tells you you exceeded the $750,000 mortgage balance limit, if it told you that at least you would know something is wrong
Okay, I think I am hit by the bug regarding mortgage balance double-counting, which is lowering my mortgage interest deduction enough to put me in the standardized deduction category:
I refinanced in 2020, then the loan was transferred a few days later. So I had 3 entries in the mortgage interest worksheet. But when I delete 2 of them and just enter my total mortgage interest and property tax for the year in a single entry for just the one bank, TurboTax now picks itemized deductions and my numbers seem to be correct.
I'll wait for the bug fix for this, obviously I want to have the actual information from my 1098 forms.