Apple Music family sharing not working in Japan

Im studying abroad in Japan and switched my app store region to Japan in order to download an app. I'm also using a Japanese SIM with a Japanese phone number. Before I switched both of these things apple music was working in Japan. After I downloaded the app I switched my region back to the US because it was more convenient. Now it says im no longer subscribed to apple music and need to rejoin. However I have apple music through family sharing and my Dad hasn't changed our subscription at all. How do I fix this?