Long term cap gains tax being taxed as short term gains?

I am in the highest tax bracket, and I have long term cap gains of $50k.  From what I understand, these gains should be taxed at 20%.  However, the system is entering my long term gains into Schedule 1, and then this amount is then being carried over to line 6 of 1040 and added to my total income, with the result being it is being taxed at the highest bracket, ie the same as a short term cap gain.  Is there an error with the forms or am I not understanding something?