I had exactly this experience. My father was a Regular Navy officer. I was born in Mississippi of a Mississippi family during a short period my father was a civilian (unhappily). He was recalled before WWII. After a tour in Washington we moved to NYC where my father was stationed and then went overseas. In the NYC schools I was individually tutored and forced to talk Yankee. I was even punished for saying "yes Maam" or "yes Sir." Tough stuff for a 1st /2nd grader. It got better when we moved to the suburbs. It worked for me. I now have an educated middle Atlantic accent and a lot of resentment.