Random player's world appears in personal world list

When I open up Minecraft for the Nintendo Switch and click “Play,” at the top of the “Worlds” list there will be a world made by a player that I have never heard of. The world will be labeled as a “Friend’s world,” but if I go to the ”Social” tab, the user will not be listed as one of my friends, even though they show up as online like one of my friends would. Also, it will be a different user and a different world every few minutes. This has only been happening for a few days, and I am not sure what caused it or how to stop it. I am 100% sure that I have never friended any of these people. I’m not sure if this is a bug or something else…