Poor Vuforia image targeting on iOS

I built a Vuforia project that works great on my Android Pixel. I just switched it over to iOS and tested it on a iPad Mini 3 only to find out the image target floats around like crazy as the device moves. I don't have any other iOS devices for testing but I'm hoping this isn't typical of Vuforia on iOS. Does anyone have any experience with this? I built a test scene with only a single cube in it to make sure it wasn't my project and I got the same results. The cube drifts all over when the device moves.

 

Update: I was able to run it on my wife's old iPhone 5 and it worked fine. I guess the minis just aren't good enough.