GranEye

Today I bought the GranEye for my Winmau Blade5. I have big problems because of its inaccuracy. Every third dart is wrong. My Setup is with an iPad Pro but dont have a lightring, only light from above. The Wifi is semigood. How can I improve the setup? Does somebody have the same issues with GranEye? Is it the light, the Wifi or both? Please help :)