I own a realm where a nether portal system exists between the worlds, however, once making a second system which works from overworld to nether, the return journey from nether to overworld, the message of building terrain appears and the noises and music continues, however to access the overworld, I have to close my Minecraft application and re-launch it. It then spawns me away from my nether portal in the overworld but nearby. This is on the Xbox One edition of Minecrsft Realms.