Following the "sign out" into a new tab results in 404 Not Found
I'm honestly not sure what is going on here.
Once I'm logged in to a Codidact site, if I click "sign out" in the top right corner of each page, I get signed out -- which is exactly what you'd expect.
However, if I follow that link such that it's opened in another tab -- Ctrl+click, middle-click, right-click then "open in new tab" -- what happens is that I get a 404 Not Found error message back.
The URL then shown by the browser looks perfectly sane in that case;
https://somethingsomethingoranother.codidact.com/users/sign_out (which is the same as the link target).
If I go back to the original tab, and simply click the exact same "sign out" there, then I get logged out just fine.
This is with Firefox 68.9 ESR. Thinking that this was somehow related to too-strict privacy controls, I tried setting uMatrix to allow everything globally, but even then I got the same error message.
It's a slight annoyance because I sometimes like to leave posts up for reference, but want to sign out of my account. The standard way to do that for me is to just middle-click "sign out" to sign out in a separate tab, leaving the others untouched; but in this case, that doesn't work, so I have to open a new tab to somewhere on the site, then sign out in that one.