Firefox 37.0.2 ignores porn mode, how to fix it?

Question

Browsers

Good afternoon,
I have several MacOsX users with the latest version of FireFox.
Users want to log into the site both under the admin account and under the account of a normal user.
Before that, everyone did it.
In a normal browser tab, they visited the site under a normal user.
Then, in Firefox, they opened a private tab and went under the admin.
But, for some time now, FireFox has begun to ignore all privacy settings and takes cookies from a regular tab for a private tab.
Users, as usual, "we didn't change or touch anything, it's the way it is"
How can you help the monkeys?

Answer 1

Artem , well done.
AlexLIn , I also didn’t immediately understand what kind of porn modus, but I appreciated it from the side of the headline, it’s well written.
The advice is obvious, roll back the version until a solution is found.
I don’t see such a problem on Windows, but in private mode for some reason the master password for passwords was not requested, and everything was inserted into the windows with the password. And this means changes in the “private mode + authorization” bundle were carried out.

Answer 2

Yesterday I installed firefox updates, and everything with anonymous tabs works there, it does not pull up any cookies from a regular tab. The problem is contrived and it seems to you that you are just too lazy to reach the user and figure it out.