I finally figured it out, and it wasn’t too difficult. HOWEVER - the Plex server software automatically moved all friends that were part of “Home” to the “Friends” group when attempting to add an additional account to the Home group (it stated that I had 15 Home users already). That disabled Fast User Switching, because accounts in the “Friends” group don’t have that ability. If this is clear in the Plex installation notes somewhere, please let me know.
Basically, I confused users with email addresses (friends) as being Friends that were simply in the Home group and assumed that they didn’t count towards the limit. I now understand that they can be in both places, but “Home” has a 15 user limit (obviously) and enables Fast User Switching. To move them back, another email confirmation is sent out to them when you choose “Add User” -> “Create A Managed User” in order to add them back to Home. Now for a drink!
