Mine has similar behavior, it moves the cursor if I slide my finger on it when in numpad mode, but if I press the numbers in a field, it insert them. From what I remember, months ago, when the mousepad was set to numpad, the cursor wouldn't move.
Anyway, Asus seems to outsource the software because no way a company this big can mess up any piece of software they put out there. Like really, you find open source code on Github written by a student that is more stable than what Asus releases. Is like they don't even run the software to check if it works.