Income you earn by working in MO is always MO-source income. If you file your KS return as a KS resident, the MO-source income you earned during your period of KS residency becomes taxable by KS as well as by MO. But you would be able to claim a credit on your KS return for taxes paid to MO on the income that is taxable by both states.
The KS web reference I gave you previously states that you can file your KS return either as a resident or as a non-resident, and suggests you run the figures each way to see which option is better for you.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
