Multiplayer toggle greyed out.

创建一个地图时，我打开了多人游戏的选项，但是进入游戏后，多人游戏那一栏是灰色的，也就是强制关闭的。

并且我用xbox live 邀请我的好友时，他们是没有收到邀请函的。

注明 我使用的手机是iPhone 9 。

When creating a world, I turned on the multiplayer option, but after I entering the game, the multiplayer column is grayed out, which means it is forcibly closed.

When I sent an invitation to my friends using xbox live, they didn't receive it