Thanks so much for looking into this!

Unfortunately there's the same problem... When I log out and try to log back in, it automatically logs me back into my account, and no prompt is given for my nephew to log in. Also, when I log in to factorio.com, I can see my account is linked to the Nintendo ...

I have bought Factorio for several of my family members over the years so we can play together. I bought it two days ago for my nephew on his Nintendo Switch. When I started it up and went to verify cross-platform multiplayer was working with a server I was running on PC and it prompted me to log in ...