Earlier, I tried publishing one of the subplaces for a game I work on. This was the resulting popup window.
Upon further investigation, the account was in studio, but not in team create on the start place or any of the subplaces. They are, in fact, a child working on a template game on their account.
I’m not entirely sure how this happened, but it looks like somehow a random user in studio on a completely different experience was detected as being in team create on my experience. They are not in the group, and have no access or permissions whatsoever anywhere. The warning appears to be completely incorrect/invalid.
I’ve included the experience link/account in the private message.
A private message is associated with this bug report