I moved from MO to MA but MA is taxing me on my total earnings even though the amounts are broken up by state, why?

As a part-year resident, you're generally taxed on all your income while you're a resident of Massachusetts, received from sources inside or outside of Massachusetts. Massachusetts gross income is income earned from all sources while a Massachusetts resident.

Mass.gov

Since you moved from one state to another you'll need to file part-year returns in both states.

You need to make sure you've set up your personal information correctly in TurboTax. You will allocate your income between the two states. We'll either ask you to separate the income you earned or to verify the allocation amounts we already calculated for you.

 How do I file a part-year state return?

How do I allocate (split) income for a part-year state return?