How do I enable iOS badge clearing?

When receiving a notification, the badge count is increased automatically. The badge correctly disappears on opening the app. But with every new notification, the badge count keeps increasing, it is never cleared.

I have tried setting OneSignal_disable_badge_clearing to NO in the following two places, but it doesn't change anything

LeanIOS > Supporting Files > MedianIos-Info.plist

OneSignalNotificationServiceExtension > Info.plist