Can't join in same room with android and iOS device

This is my explanation.

· iOS and Android users belong to the same daimyo (clan) and are located in the same country.
·Attacks on neighboring countries on iOS move to battle scenes.
On Android, at the same time, you can see that a flame icon has occurred in the country where iOS attacked, and that the battle has taken place.
·Android users can tap the flame icon to join the battle room where iOS is participating, but even if they participate, they will not be able to join the same room as iOS, and a new room will be created.
·The opposite is true: iOS users can't join even if they tap flames to enter Android-created rooms.
·If Android user A and iOS user B' belong to different daimyo and the daimyo belongs to adjacent daimyo, if A attacks B (or B attacks A), it should be synchronized correctly to the same battle room and real-time battles should not happen.
·In addition, there is no problem between the same OS, and the battle is synchronized.
It's how to enter the world of Fumu.