Gratis to drrossba and fhydeaz, but I now think the crux of the problem is how TT implemented the "85% Waiver" which is new this year. Otherwise, the Form 2210 is the same as it was in 2017. What TT should have done is invoke their 85% waiver worksheet only if the penalty calculations of Part III or Part IV show a penalty is due. TT's program automatically did the Regular Method for me both last year and this year. If no penalty is due from one of these Methods, then the 85% Waiver worksheet should be left blank, which will leave Box A blank, and there is no problem. TT's mistake was filling in the 85% Waiver worksheet when it was not needed, which triggers the X in Box A. You can fix TT's mistake by overriding the X in either the worksheet box or Box A. Commenter inventor27798 nailed this five days ago in his/her comment in the string.
