I've only noticed this behavior recently but it seems EWBF is taking a 50% devfee.
I've disabled their software and highly recommend, regardless of the software you're using, that all miners ensure the actual devfee is what the devs say it is
I highly recommend, regardless of the software you're using, always download the mining software from the official bitcoin forum post , in your case from here :
EWBF's CUDA Zcash minerIf you are dowloading any miner software from random websites, you are basically calling for trouble ...