If you have not changed your domicile, then you are still a NY resident. You must file a NY resident tax return (not a part-year resident return) that reports and pays tax on all your world-wide income. You must also file a Maine non-resident return (not a part-year resident). The Maine non-resident return will calculate your tax based on Maine-sourced income (like a part-time job, side gig, etc.). Make sure to tell Turbotax you are a NY resident and a Maine non-resident, and prepare the Maine non-resident return first. If you owe Maine income tax, you should get a credit on your NY return that will reduce your NY tax accordingly.
Your domicile is your permanent home, and you only have one domicile at a time, even if you have several homes. If you maintain ties to NY (legal, financial, medical, social) and intend for it to be your long-term home, then you are domiciled in NY even if you live in Maine for most of the year.
