It's likely his account is restricted for inactivity. If he wants to shop, he should contact the Help Desk and ask to be reactivated. You should remain uninvolved. I doubt his restricted activity has anything to do with you.
MF frowns on one person registering twice with different names but the same information for fraudulent purposes but not multiple people at one address. A family member shares an address, home phone, ip address, and sometimes a computer with me. We've both been fairly active with MF for 7 years. The only way this would be an issue would be if one of us were deactivated "for cause." If my family member were deactivated because MF believed he was doing something fraudulent, they would likely deactivate me also. They do this to protect themselves.. If they deactivate someone, they do not want him to be able to access their website. If the deactivated shopper lives with another shopper, in MF's eyes, the deactivated shopper could get in to their website by using his family member's computer. Even though it means they sometimes lose a good shopper who has not done anything wrong, they want to block the ability of a deactivated shopper from getting back in.
It was very easy for you to log into your husband's account just to look at job availability. I'm not saying you did anything wrong, but think about it. It would be just as easy for your husband to log into your account. If he had been deactivated for some fraudulent action, or if he had been deactivated for no reason and he was angry, he could use your account to get in. To protect themselves, they frequently block the whole family. This makes deactivated shoppers believe they were deactivated because multiple family members were shopping. Not true. They were deactivated as a means to completely block access to one of the family members.