Once again James, sorry for not getting back to you sooner.
The situation remains the same, in as much as a press of the 'phones' button does not bring up the latest Windows Phone stories. However, I have taken a closer look at this today. It seems to me that it's because the filter isn't actually picking up all the Windows Phone related stories, only certain ones. At the top of each story is a grey box indicating the subject matter e.g. Xbox, Microsoft News, or Windows Games etc. I've noticed that the filter only brings up stories headed 'Windows Phones.' It completely ignores those headed 'Windows Phone Games', or 'Windows Phone News', or 'Window Phone Apps' etc. These should be included too. I thought the filter was there so that people who were only interested in, say, Windows Phones could filter all the other stuff out, but in using this button we are filtering out the bulk of the Phone news too!!