Why YSK: after yesterday’s security incident many instances have reset the session tokens which your browser remembers. This is causing issues.
You need to clear cache / cookies / app storage, etc… to eliminate any login problems or problems staying logged in.
I’ve seen many posts mentioning this already.
I have Firefox set to automatically do all that whenever I close my browser but it’s still somewhat of an issue on kbin. Not enough to bother me but it happens.