When i "sign in with email" and "sign out" on this board it keeps me logged in, thus preventing me from signing into other accounts. Have use two different browsers or clear cache to fix. This is the only site on interweb that does this sooo...

 

 

Its not this site. Its the cookie from the main site. They use SSO here so if you don't sign out of both here and the Client Area you'll likely be bounced straight in on this part of the site. That's what SSO does.

To the extent that a button doesn't do what it says it does it is the site.

From a UX and security perspective, it's broken. See this thread: