If your game account is bound to Facebook, but the friends list in the game does not display your Facebook friends, please try to unlink the game to FB and then bind the FB account in the game again.
If you still have problems, please report them to us in the feedback form of FB friends in the bug feedback of customer service.
If you don’t want to sync your FB friends to our game, you can try the following steps:
Open your FB App, click Settings -> Application and Website -> log in with Facebook account, click edit to find our game, click view and turn off the switch of friends list.
Game Guide for Mobile Legends – moonton