If you see the UIInput script, it doesn't send "OnInputChanged" message on this platforms.
I had to change on "Update":
if (mText != text) mKeyboard.text = mText;
UpdateLabel();
To this:
if (mText != text) mKeyboard.text = mText;
UpdateLabel();
SendMessage("OnInputChanged", this, SendMessageOptions.DontRequireReceiver);
Hope you fix that in the next version.
Thanks!