Board Thread:Support Requests - Getting Technical/@comment-4519283-20130530001834/@comment-452-20130531141647

Wikia staff are aware of the problem of highlights from one wiki continuing to be shown after going to another wiki, but this sounds like a different problem.

Are you talking about a highlight, or a message wall notification?

If someone posts on your message wall on a wiki you've never visited, you should get a message wall notification, but you should not get a new forum highlight notification unless you visit a wiki.

This sounds like a bug, so you should report it using Special:Contact.