Sounds like it is working perfectly.
The loader uses intelligent feedback to know when it doesn't have paint in it.
That's why it's slowing and stopping to try and get balls to feed.
If the loader is empty and just spins quickly all you get is popcorning, no feeding, and broken paint, and that's why we actually program it to slow down and even stop briefly if there is no paint in it.
Put it on your gun and shoot paint, and you'll see that it is just fine.
The loader shouldn't have come out of the box on setting 6, are you sure it was? I'd turn it down to 3 or 4.