I moved states (from MD to NY) this year to start a new job. When I entered my NY W2, my MD return changed. Why would a W2 in NY affect my return in MD?

The change was pretty dramatic - I went from receiving a refund in MD to owing over $1000 in MD. I checked that my W2 for my MD job is listed in MD, and my NY W2 is listed for NY. This feels like a glitch but can't figure out how to correct it.