Account Issues/ Multi-player Required

A few months ago, I played Halo 5 Guardians during its free days with gold. After a while I removed it. Yesterday I bought a hard copy and played the game. Solo play was fine, but when I wanted to do multiplayer, the “Multiplayer Required” Notification came up. I have an account with both xbox live gold and online privileges, but it claims I don’t have gold. Can anyone help me?