Notification indicator shows double the amount on desk

Hi all,

I created a custom app to better calculate manufacturing costs and want to show all “Open” Calculations as an indicator on the desk.
I’m not sure, weather this is a bug or it’s just me, but the notification count in the notification panel on the top right shows the correct count, but on the desk the number is always doubled.

def get_notification_config():
notifications = {
    "for_doctype": {
        "Calculation": {
            "status": ("in", ("Open"))
        }
    }
}

return notifications

Is there anything else I need to do for the desk notifications?