It is possible to logout from this forum and to continue to appear logged in in another tab/window. Normally Discourse forces a refresh on other tabs so I would appear logged out in all of them. In this case, I look logged in and can view everything but I cannot actually edit anything:
If I have the main menu displayed as shown below then I can log out in another tab and come back to this tab and the refresh has not been forced.
I would happily report this issue at Discourse but I can’t reproduce this there on meta.discourse.org. But when I view the page source of both sites I find the same version number. So I’m confused. I’m not sure why I found this bug here but not at Discourse. Are you actually on the latest version?
Here’s examples of different tabs showing me logged out in one and logged in in the other:
You can see how I navigated to my user card.
I could even log in with another account in the logged out tab and have no change in the “logged in” tab as long as I had the main menu displayed.
This may be a related issue on Discourse: