I've tried going to the top-right bar > down arrow > Sign Out > Login page > press Sign Out > computer loads for a bit > Still on Login page, not logged out.

Browser: Firefox (up-to-date).
OS: Windows 10 (up-to-date).

Is anyone else getting this issue?

On iPhone 5s on Safari, sign out works normally. Also works fine on Edge and IE 9 on Windows 10.

Before the recent update for Windows 10, sign out worked normally on all browsers.

Mailed Fizzer.

You could try clearing all browsing history including autofill data, passwords and hosted app data? It will sign you out on websites but i use chrome and don't know firefox well.

I use win10 and firefox (latest i think is 45.5?) and i was able to log out.

Dan, you fool. Don't you know we are never supposed to leave!?

Seriously, I have never had this, probably submit it as a bug report.