Interesting story Dave if unusual on such a new car and an excellent start to fault finding. Can I ask what the breather was blocked with?
Richard, it appeared to be plastic swarf from manufacturing, it was totally blocked and fortunately I had a high pressure airline to blow it through.
My thoughts are this may not be a one off and other cars may be affected, one thing has proved to me is that this site is invaluable to us owners especially those that live a considerable distance from a dealership.