Just as a comparison, I also did my daughter's taxes. She has $0 direct contributions on Line 2, $3,6500 on line 8 (she's single), and the $2,000 contributed through her employer on 11.
Line 12 calculates the $1,650 under the maximum accurately, and then correctly calculated the smaller of 1,650 and 0 to be 0 for line 12.
So hers seems to do the math correctly.
