Left nav pin/unpin should be a global, cross-site pref
I set the preference to collapse the left side bar (“Hide left navigation”) via Meta Stack Overflow, and it's working there. But on Stack Overflow and Meta Stack Exchange, the left side bar is not collapsed and the preference checkbox in my profile is unticked.
User interface preferences should obviously not depend on the site. I'm not going to edit my profile on over a hundred site!
Yes, I know this is an old bug, keyboard shortcuts have had the same problem for years. So please solve it already!