@rjs --
Page 3 of the instructions for Arizona Form 309, Credit for Taxes Paid to Another State or Country, has a full section on Dual Residency. It states:
You may be eligible to claim the credit if you are a full-year Arizona resident filing Arizona Form 140 and you are also considered to be a resident of another state under the laws of that other state.
https://azdor.gov/forms/tax-credits-forms/credit-taxes-paid-another-state-or-country
I believe this would apply in the OP's situation.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
