C&P exam AFTER they gave me a decision letter?

So I filed a claim back in Sept, just got an email saying that my decision letter is ready. When I go on the VA app my claims history shows the claim has dropped back to step 3, but they also have my letter showing their decision.. what exactly does this mean? They decided to give me 100% but they need more evidence AFTER deciding? My nerves can't handle this someone please help me understand :/