The mystery of the missing bet

I placed a matched lay bet last night on an antepost market which is yet to be settled.  The profit on the lay has reduced as if the bet was struck, but the profit or loss has not changed on the other runners.  Basically, according to my p+l, I lose if it wins as if the bet was struck, but I don't win if it loses, as if the bet wasn't struck.  The bet does not appear in my matched bet list to the side of the market or my bet history.