State tax filing
You said: "I went to W2 and changed..."
The screen How Massachusetts Handles Income for Nonresidents in the Massachusetts nonresident state tax return apportions your W-2 income by one of several methods. You are not advised to actually change any amounts on your W-2.
You state that Massachusetts income box 16 of the W-2 differs from box 1 of the W-2.
Has your employer already apportioned your box 1 income for the Massachusetts amount? For instance, if box 1 was $30,000 and box 16 was $20,000, has the employer already made an apportionment?
See also this TurboTax Help.
