I stayed at a place last week just like this, but the max was 9, not 10. If you get to 9 and press '+' again, it resets to 5! From there, pressing '-' goes down

I stayed at a place last week just like this, but the max was 9, not 10. If you get to 9 and press '+' again, it resets to 5! From there, pressing '-' goes down to 4, not back to 9, so press '+' another 4 times to get to max.