Yes, it would be considered "Remote Work". Technically, you would be responsible for KS income tax for the period of time you physically worked in KS.
Did your employer withhold MO or KS state tax from your paycheck? Before COVID, did you file a MO non-resident tax return, pay MO tax on your earnings there and then file a KS resident return claiming credit for the tax paid to MO?
Normally, this is what you would have done: You would file as non-resident for MO (for your MO source income only). You would also file a KS resident state tax return (for all income from all sources including MO). You would get a state tax credit in KS for the MO state taxes you paid on your nonresident MO state tax return.
The only difference with remote work, is that you would have less MO income to report (and pay MO tax on), Your remote income would be taxed only by KS.
