Hi. I need help understanding why my NY Tax Due increased when I input my Vermont non residency W2 information in?

[SweetieJean]

NY (as your home state) taxes all of you income, regardless of where earned.  But see:

https://www.tax.ny.gov/pit/credits/resident_credit.htm

However, if the NY tax rate is higher than the VT tax rate, you owe NY the difference on that VT income.