I saw that there's a Lifespot group and I can read the messages in there even though it's marked private. I put in a request to join before I realized that I could see in there already.
I can read the Private Group
Hmm, that's very strange. Definitely need to work on permissions there!
Hmmm.
Public = Everybody can see the group and can view the content
Private = Everybody can see the group but can't view the content
Secret = Nobody can see the group.
The backend logic looks right on first inspection. Let me keep looking for this as there is certainly a bug there.