I found this 2015 £2 coin in my change the other day , to be honest it looks like a proof or at least an ex set or something , the thing that made me check it twice was the prooflike appearence , it just seemed interesting .
After checking out the coin I suddenly realised it has no "STANDING ON THE SHOULDERS OF GIANTS" on the edge this is really dificult to picture but trust me there is just the normal reeded edge and no sign of the letters which appear on all £2 coins 1998-2015 to the best of my (little) knowledge.