After you completed entry of the Form SSA-1099 for your Social Security benefits, there was a screen which asked you if you lived in any of the foreign countries listed. If you did NOT live in those countries you should have selected NO.
If your benefits are showing as not taxable and they should be then you need to go back and look at your answer on that screen.
To enter Social Security benefits reported on form SSA-1099
Click on Federal Taxes (Personal using Home and Business)
Click on Wages and Income (Personal Income using Home and Business)
Click on I'll choose what I work on (if shown)
Scroll down to Retirement Plans and Social Security
On Social Security (SSA-1099, RRB-1099), click the start or update button