I made 36,706 in Missouri yet the state return calculates it to be 58,295? Why is this?

I assume that your federal AGI is something like $58,295?

"If you were a Missouri part-year resident with Missouri source income and income from another state, you may use Form MO-NRI or Form MO-CR, whichever is to your benefit." See page 3 of the MO-NRI instructions.

So Missouri has two ways to deal with part year residents and nonresidents.

The first is that you can take a credit for the other state's taxes paid. See form MO-CR.

The second is that Missouri calculates the ration of Missouri source income to total federal income, and multiplies your federal income by this ratio. See MO-NRI. I assume this is what you are seeing.

You are allowed to choose either one, whichever is to your benefit. I imagine TurboTax will make the better choice for you.