This is deliberate. It's a matter of risk. Either you sit with your best score, or try again and risk getting a worse score. The popup message when you go to retry warns you of this.Suppose at first attempt I Played and get 7 ball without boundary second time it took 2 ball then my previous ranking is overwritten , It would take my Highest attempted ..
It means you can't just infinitely retry - you have to be sure you can better your score if you try again.