I'm also having this issue on Win10. Realm takes few minutes to connect, then all of the players online in realm disconnected randomly with the message of "Disconnected" or "Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host". I think the issue of getting kicked is because of the auto save function. Almost every time the players online got kicked of "Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host" is because of the server auto saving.
TheRailway
I'm also having this issue on Win10. Realm takes few minutes to connect, then all of the players online in realm disconnected randomly with the message of "Disconnected" or "Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host". I think the issue of getting kicked is because of the auto save function. Almost every time the players online got kicked of "Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host" is because of the server auto saving.