opening about:preferences#privacy from the security toolbar button leads to adding about:preferences#tor items at the end of about:preferences#privacy
Someone reported this on the blog: https://blog.torproject.org/comment/285516#comment-285516
Using the icon on the toolbar to change the security level is showing the "Privacy & Security" and "Tor" settings in the same pane, while they are in two different ones when opening them through the hamburger menu and selecting "Preferences".
I am not sure if it is a bug, or if it is intentional.