Why am I getting a so little refund back. It even cut down my child tax I was supposed to get back.

I put in my first w-2 and I was supposed to get $3,700 back plus over $30” in state. Then I put in my second w-2 and my refund dropped down to $1300 and I now owe the state. I also have a kid and I should be getting $3,500 already, but no.