League Red Notification Bug

In the application section of our league, there is a request that remains even if we reject it. It seems to be bugged, and we can't remove it. No matter how much we try to delete it, it always stays there. It appears as a red notification badge, and because of that, we can't see the actual important notification messages. This is seriously affecting us. All Admins have the same issue(including owner too) in our league. Please tell us what we need to do.

The bug looks like image in the below

The date and time you think the problem started

Maybe five months ago.