Now, using Firefox, every time I log out I see a red pop up message which reads "You do not have permission to do that." This may be a known bug but it's a new one to me. I have just logged in and out using Chrome and Edge but couldn't replicate it.
Edit: have just logged out using Firefox and the pop up didn't appear, so perhaps it's intermittent.
2nd edit: tried again using Firefox and it appeared.