Submission indicator shows 1 even though all submissions were deleted

Hello, there is a stuck notification on one of our forms. It's showing there is 1 submission when there is actually none. I can not seem to make the notification go away. It's bugged or something. 

Sorry for the inconvenience. It is possible that a submission was deleted without viewing it. I have fixed it for you. Here's a screenshot:

Thank you for your understanding.