qbteach: You nailed it!  Proseries created the error.  The "cross reference instructions " in Proseries for Form 2210 Line 2 in the 2020 software says "From Schedule SE, line 12 minus line 26...."  I was surprised when I read the IRS instructions for the same line it nowhere says to reduce by Line 26 of Schedule SE.  

I spent 5 hours on the phone with Proseries this morning and have 2 cases open and escalated.  Their position so far is that I should have reported zero on Schedule SE Line 18 and that would have made the estimated tax payments for 2021 calculate correctly.  I tried to explain to them that Line 18 is not a discretionary number and entering zero on that line would be filing a false tax return but they don't get it.  All they know is that the software is "calculating correctly."

Anyone have a good lawyer?