We’ve had no more interlopers so perhaps the first 2 games were blips somehow. The game was set to 2 slots with the other of course being filled by inviting my daughter. On half a dozen occasions across the 2 games someone one popped in either briefly or for a while. I was wondering if the reason that it wasn’t letting me swap to a private game was that with a 2 slot game already filled the point of public/private is moot. Anyway; seems ok now. Loving the game; it’ll never depose Minecraft for daughter and daddy game night but it’s a pleasant alternative when it’s time for a change.