So, to me it sounds like you're telling me to restart my computer because the mouse isn't working properly. If I check tomorrow at the same CET time (21.41), then they should be gone?
Well if there are only a few questions with tag "B" and you want it to be tag "A" then editing the post to remove "B" and add "A" is the quickest and easiest thing you can do.
But as this bumps the post to the front page it becomes a problem if "B" is attached to 15 or 20 questions. In that case proposing a synonym and doing a merge is preferred as it doesn't bump the posts.