The group shown in my screen capture is set to Invite only.
Issue 1: when I left the group I could still select the "join the group" button. This should not be possible.
Issue 2: After selecting the Join the Group button, the message appeared indicating this was an open group - however this group is not open.
After closing the message I am redirected to the social timeline and an error message appears indicating I am not allowed to access this page. This message is correct, however item 1 and item 2 should are not correctly managed.
In a separate post, I am submitting a feature request recommending the addition of a Group Detail - Allow Leave Group yes/no.
Todd