If you finish it fast you get 7 points, I think it's under 5 minutes or less. Don't quote me on this lol I just now the less time the more better chance of getting the 7 points. If you go over that you will be awarded 5 points. I play this

I finished it in less than 30 seconds. I always got 7 ARP, except today.

It might be because of how many mistakes you had, i've had it give 7 points most times, sometimes 5 points randomly. I got 7 this time around.

Might be true. Never thought of that, I always went for the fastest time possible.

Sadly it was a known issue earlier, not sure why it happened, some people with 1-2 mistakes still got 5 ARP only.