This is a bug in TurboTax's error checking. The entry on line 26 of the IRA Contribution Worksheet is actually correct, despite TurboTax saying otherwise. Everything else in TurboTax is handling this entry correctly, it's just the error check for this line that appears to be failing to compare to the amount on line 10 of the IRA Information Worksheet.
@Katie_B I've uploaded Token 743629 demonstrating this bug.
[Edit] This worked fine in 2019 TurboTax R49 and became broken in 2020 TurboTax R1.
