Hi Alex,
Look Alex, it appears I'm more confused than you!!
I have explained what happened before the upgrade and although I did not use this function often I believed it to be a part of the program engineering and design. Now it seems you are saying this was a bug which you were not aware of?
You further say V4.2 has been changed, but for me the radio buttons have no function in your new version 4.2. However I toggle them and save there is no difference at all.
I've read the tool tips and to the best of my understanding if I've used Facebook authentication and I've not logged out of Facebook I should remain authenticated upon leaving and returning to the site?
As there is confusion about how exactly it was and how it is now, I wonder if you would be so kind as to be explicit about the intended function of the four radio buttons, that is,
Auto Login Facebook Users: Yes No
Logout Of Joomla Only: Yes No
As I mentioned there is no difference in any combination and that is really confusing.
Hopefully we'll get to the bottom of this soon
Cheers!