Oh goodness, I found my error. On the “Tell us about” page for the dependent, and under “This child is...” section at the bottom, I had accidentally clicked on “none of the above” which then is listing him as “adoption final before 2019”. He isn’t adopted, and that’s what removed him from the child tax credit.
You can’t unselect this option so I had to delete his information entirely and re-enter it again making sure to not click on anything I shouldn’t be. Good lesson in slowing down and not being click happy.
