After leaving a realm by opening a new tab and rejoining it without restarting Minecraft i cant join the realm without restarting minecraft again and it comes up with a error message

After leaving a realm (by switching to a different tab on my computor) and rejoining it without restarting Minecraft, i cant join the realm without restarting minecraft again and it also comes up with a error message which says "Disconnected Due To The Server Being Unavailable" when the server is available. Please fix this, even though it is a minor bug it still annoys me.