I have a minecraft realms that I play with my friends in Windows 10. So, we have 4 people playing that realms, it can support 10 players. I have buyed a Minecraft for Windows 10 to one friend to him play with us. But, after 1 or 2 minutes after he log in, he gets a infinite lag, and can't do nothing, he can't even see what's happening. We already tried to close and open the realms again, log out all others players, but nothing working. We have tested too if him can enter in a world that isn't the realms. And we can play normally. So, I think that the problem is the realm itself