Because it's the same Algo i think.
Also, there are problems with hashrate and that is because your pool might need a faster internet connection to accommodate the users or you need to disable the torrents. I'm not joking, or if is nothing of what I said then it might be something holding your pool internet connection back cause the hashrate is nothing like used to me.
Maybe the payment is not as good as antminer because of the internet connection issues. Download and upload speed is the key here, need to be top notch.