I was advised by customer service to send it in as a bug.
Here's the screenshot:
https://imgur.com/a/qcKJXDq
So, in actuality; the games *weren't* set up as open; they were all set up as restricted; but - for some reason - the system will assign another game (in this case, started by Cuadrix) the same ID # and then place me in there (even though I haven't signed up for the game.
This is why I didn't feel badly abandoning them (and had my reputation restored)

- I never intended *my* games to be open; and I also didn't agree to be randomly placed into another's game. There's definitely something wonky/broken.
No one else has experienced this? We were trying to do something similar to how * works - where you set up a game, restrict it, and then post the link; and only those with the link can join. That's what this *should* do; but - clearly - it doesn't. :/
*Moderator edit: please do not specifically name other gaming platforms