I built a spawner that is completely overpowered in 1.8 and it worked flawlessly, but in 1.9 there seems to be a weird bug where it doesn't work as efficient in survival as it does in creative, I will upload a few screenshots in the near future, but it might just be happening because my world is the middle of an ocean, but I've noticed about a 98% inefficiency in survival as compared to creative, this is a vanilla spawner that I have come up with myself, so you might have put something in that broke it, but like I said, it might be purely location.