Why is my husband's income made in our residence state getting taxed in a nonresident state, even though I put that he made $0 in the nonresident state?

I live in one state, but work in another, so I have to file a return for both states. For some reason, the nonresident state is taxing my husband's portion of income at $120, even though it's showing $0 earned from that state. Why would he be taxed on money not even earned in that state?