Sgt. Bowe Bergdahl hasn’t spoken to his family since he was released from captivity in Pakistan, according to an Army official.

Sgt. Bergdahl has refused to see his parents or speak to them on the phone, the official said. The decision by Sgt. Bergdahl, who returned to regular duty on Monday, suggests a deeper estrangement between the soldier and his parents than the military understood when he was released. Still, officials said, they don’t know the precise cause of the tension or when it began.