I am a resident of Michigan but must file a Ohio tax return because I have royalty income in Ohio. Unfortunately, TurboTax transfers all my income to the Ohio tax forms.

 It only appears that Ohio is taxing all your income.

Ohio does a convoluted tax calculation for non-residents/part year residents. It calculates tax on total income, then it calculates a non resident/part year resident credit, which it subtracts from the tax it calculated on the total income. The credit is calculated as your non-Ohio income divided by Total adjusted Income multiplied by the total tax. TurboTax (TT)   does this by allocating your income as either Ohio or non-Ohio. W-2 income will be allocated by the state name abbreviation shown in box 15 of your W-2. TT will ask you, item by item, in the state section, how much of your other income is Ohio or non-Ohio income. Make sure that your non-Ohio wages show MI in box 15 of your W-2 screen, with the MI amount in box 16.