Several of my members including myself do not get notified of threads that are moved into a forum we are watching. What possible things could be causing that? fyi, we did some tests and made sure the checkbox was marked.
It won't give you a duplicate alert. For example, if you're watching the forum the thread came from, you'd already have received an alert/email regarding the thread, so you won't receive another one when it's moved. Otherwise, it really just behaves as if the thread was newly posted directly in that forum.