WII U PRO Controller - IOS 8

I purchased a WII U PRO controller to use with RetroArch.

I’m using an iphone 6+ with BTstack and Controllers for All from Cydia. It all seems to work great except the left analog stick seems to have 2 buttons detected when I push it forward half the distance, compared to when I push it the entire way. Its playable if I just keep pushing the analog half the distance in all directions. It is hard to get used to though. Is there something I can do to fix this?

I ended up taking the controller back and getting a PS4 dual shock. The PS4 controller works flawlessly.

I’m guessing BTstack or controllers for all misreads the analog motions and will need updated before this is fixed.