Each state has their own rules on residency for tax purposes.

AZ https://azdor.gov/sites/default/files/PROCEDURES_INDIV_1992_itp92-1.pdf

CA https://www.ftb.ca.gov/forms/2020/2020-1031-publication.pdf

etc. If you are physically out of the state for the given period, you are no longer a resident of that state. I think the CA publication has some excellent examples and they likely translate to other state rules. I find it hard to believe that some is (for tax purposes) a resident of two states.