Advanced Child Tax Credit

Turbo tax asked me to enter the Advanced Tax Credit received on schedule 8812 for both myself and my husband. Essentially entering the same amount twice. But when I did this I immediately saw my tax owed amount drop by almost $1000. Why is that? Does this sound correct?

 

I would think this amount entered should just offset the tax credit we qualify for but not reduce the taxes I owe?. Did I make a mistake somewhere?