change filing status on 2019 return (amendment)

My husband is active duty military with residency in Texas. In 2019, we lived in Delaware (my domicile; his location due to PCS). Turbotax recommended that we file "married filing combined separate." However, in doing so, his military earnings were taxed in Delaware where they shouldn't have been. I tried filing an amendment through Turbotax but cannot change my filing status to "married filing separate forms" like a state auditor suggested. We ended up owing money to Delaware because his earnings were taxed. Otherwise, we would have received a refund. And now we live in Guam. Please help!

 

I tried to call Turbotx to speak to a person but was unsuccessful