Thank you for the help, that saved me a decent amount of money.
It looks like there might be an error on your form 2210 for "total tax withholding for all four quarters" page. The dates are not correct, I entered a running total by actual quarter (Jan-Mar, Mar - July, etc.) here is what appears in the step by step inside TT:
1/1/2020 - 7/15/2020
7/16/2020 - 7/15/2020
7/16/2020 - 9/15/2020
9/16/2020 - 12/31/2020
I calculated by month's start to month's end, adding the 15 days seems to not accurately show quarters.
