VA CLAIM WAS DEFERRED

So i originally claimed increases for my service connected ITBS bilaterally and lower back pain and sciatica secondary to the already service connected ITBS. I was denied for the back and sciatica and my increases were deferred….then I was sent to another C&P exam for the back and sciatica even though it was already denied. Im a little confused as to why that even happened, has that happened to anyone else?