I set up parental controls on my child’s phone now the Apple ID is not highlighted anymore

You must have set a restriction to prevent them from signing out.

Which specific restrictions prevent signing out? I just removed all the restrictions I could find from my daughter's new phone and still can't sign out of the account.

Also need a response to this. Which restriction specifically keep them from signing out?

I'm having the same issue. What is the guidance?

Did you try restarting the phone after removing the restrictions?