That (getting exactly $500) usually means your child turned 17 during 2019.
You can still claim your child, as a dependent. What you can't claim is the Child tax credit. This comes as a big surprise to many parents the year their child turns 17. A child over age 16 no longer qualifies for the Child Tax credit (CTC). Although a child can still be a student dependent through age 23, and a qualifying child for EIC, the Child Tax Credit expires the year they turn 17 and you no longer get the $2000 CTC. Instead you will get the non-refundable (up to) $500 Other Dependent Credit.
Otherwise, you've most likely entered something wrong. In the personal Info section, for the dependent, you must select answers that indicate that he/she is your dependent child. If the child was born during the year, say he/she lived with you all year (note: TurboTax changed how this section is done two years ago, you may need to go thru the interview again or even delete your dependent and start over). If the child was born in 2019, you have to answer that he lived with you all year. The CTC is not an automatic $2000, per child. It is income dependent. If you haven't entered your income yet, the CTC will not show.