Crosplay joining worlds doesn't really work

I am playing on Win10 and my brother is playing on Android 8! If I want to join his world it's working how it should! But if he wants to join my world it just says: "can't connect to the world"... So Win10 can join Android worlds but Android can't join Win10 worlds! I also tried it with other devices but it just deosn't work... Please fix at soon as possible because this is just not a good Better Together Update!