I've done extensive research, but to no avail. Minecraft realms has been having the issue of automatically kicking me from my own realm for "being idle for too long." I've recently discovered that the command that allows people to set the idle kick time doesn't actually work in realms. If this is a bug, then I believe that it is in the best interest of hundreds, if not thousands of Realms customers, to have this fixed. If it is, in fact, an intentional feature that Mojang has implemented, then we have a greater issue to resolve.