TurboTax finally updated Form 2210 for 2020, but incorrectly tried to use column (b) for lines 20-26 (Part IV) for calendar year filers. Please fix this bug.

[davidia998]

Column (b) should not be used, but calculations show up for lines 20-24 (and not lines 25-26), which causes an incorrect value in column (c) of line 20 (Part IV, Form 2210).

[Andy77]

I have the same problem, but did not notice the TurboTax error until after filing.  As a result of the error, any overpayments made in the first period will not be carried forward as a credit to the third period, which may result in TurboTax falsely telling some people that a penalty is owed when none is owed.