Within your user settings within the category Groups you may select a group label.
About administrator and Administrator groups
I just git-pulled and upgraded a few minutes and on the Groups page, I'm seeing that there are 3 groups - administrators, Administrators and Registered Users.
Is the lower case administrator group a type. Is that supposed to be the Moderators group?
The "administrators" and "Administrators" group both are the same group. In your case, it's supposed to be hidden, but is not. Can you look in your redis and ensure that when you run
hgetall gid:2(which should correspond to the "Registered Users" group and the "Administrators" group), that
hiddenis set to 1?