Rigidbody2D interpolate not working on iOS (Unity 5)

I use a 2D rigidbody to move a character. Due to fixed time position update the movement stutters. To compensate I use this option: http://docs.unity3d.com/ScriptReference/Rigidbody2D-interpolation.html

It works very well on Android devices, but it does not work on iOS (iPhone 6).

Does anyone else know this issue? Is it a bug? There is none filed so far..

In the meantime only manually fixing the problem works: http://forum.unity3d.com/threads/smoothmovementtest-should-help-eliminating-hiccup-sources.162694/

60 fps, Unity 5.1.1f1

Cheers, Jonas