Email used by Another Apple ID

No worries. Does the problem device show someone's Apple ID other than yours or your husband's?

And, I am beginning to think this is your problem.

It sounds like ke is trying to use an Apple ID that is, or was, in some way, associated with another Apple ID of his (e.g., as a reachable at email address or a notifications email address) in recent history. Note that you can't use such an Apple ID for an uncertain period has passed since the association ended--sometimes reputed to 30 day and sometimes 1 year. Also, I have seen that you never can use such an email address again. The last two times I saw someone claim a time period it was “up to 30 days.” I believe that up to 30 days is the current answer. But, you can contact Apple support to check out the currently quoted wait period.

 Get Apple telephone support for help using this link https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362 Be patient sometimes Apple support is closed to immediate phone support.

The association could be pretty subtle, for example, his Apple ID being used as a reachable at email address or a notifications email address. You can check these things out by looking in each Apple ID Account https://appleid.apple.com/#!&page=signin.

The Apple ID of someone else could be there if the device is activation locked. Is it activation locked?

Good for you. And, you are welcome. Be safe.