I decided to pay for a month of Realms to try it out, for my kids. The host account plays in the realm just great but whenever the other tries to join it is kicked out within a minute or two. Two different error messages, one about "timeout" and the other "remote host" closed.

I suspect you will say this is a local network problem. But do you have any idea of what sort it would be? We have a very fast internet connection and are playing on the same wifi connection. There are no connectivity problems with any other device in the home right now.

Thanks.