1098 Box 7

I've searched but can't seem to find this specific answer.  I have two 1098's for mortgage interest.   

The first one - was the original loan.  Box 7 is not checked.

The 2nd one is - refinanced loan.  Box 7 is checked. 

I have read on the boards that Box 7 is just verifying that this is the house I live in so why is Box 7 not checked on my first 1098?  And yes it does have my address in Box 8 BUT if I check it on turbo tax, it increases my tax return. Unchecked decreases my return.  Why would that change my return if it is only verifying the address??