Why won't InputEnded fire for thumbsticks?

EDIT: I BELIEVE THIS IS A ROBLOX PROBLEM

I'm trying to make a custom camera for gamepads but for some reason, InputEnded won't fire when you let go of the thumbstick, here's an example.

InputService = game:GetService('UserInputService')

InputService.InputEnded:connect(function(input)
    print(input.KeyCode) --prints unless I move a thumbstick
end)