This is kind of a strange one. As I said in a previous post I loathe the new Firefox, as most plugins (including noscript and lastpass and several others) are disabled or not available. So I chose to stay on 56.0.1 until the plugin writers can catch up.
This was all well and good for the last two updates ~10/16 or 10/17. However, with the update that just ran on my system, even though firefox is locked, it got upgraded to 57.0.
Firefox is locked, I tried locking it again, and it says “already locked.” So how is the update manager overriding the setting?