With respect to Form 2210 AI line 14 calculations, I can confirm that the calculations for at least columns (a) and (b) are wrong for me. I ran some tests with a spreadsheet using the correct IRS worksheets and it appears that line 14, box (a) is incorrectly calculating the tax effect of LT cap gains and Qual dividends. In my case, it appears that TT is incorrectly using the factor for box (b) (factor of 2.4) instead of the correct factor of 4 for box (a) for this calculation. This appears to be a carryover of the 2020 calculation which combined income from the first two periods to assess underpayment penalties and would have used the column (b) factor. Line 14 Box (b) also appears to have used the wrong factor which also resulted in a significantly higher number in box 14 (b) than it should if the calculation was done correctly per the Pub 505 IRS worksheets. There may be other explanations for the bad numbers in line 14 (a)- (c), but since previous problems with 2021 Form 2210 line 10, box (a) were also the result of carrying over the 2020 Form 2210 calculation, it could be that line 14 is messed up in a similar way.
