After you file

Did you file 2020 return yet?  You should have 1,100 (500+600) on 1040 line 30.  Was your child born in 2020?

 

Go back to My Info and make sure you said your baby lived with you the WHOLE YEAR and not just the number of months.  Even a baby was born on Dec 31 is considered to live with you the whole year.  You might have to delete the baby and re add him.  Pay attention to the questions, especially the one asking if he paid more than half of his support.