Other admins not being notified of backup failure

I have been working to hand over admin functions to other colleagues, and for some reason other admins are not being notified of backup failure. Meanwhile I am being notified twice and get two emails for it - see screenshot.

As a result I am the only one jumping to take action when this happens. Is there something I need to do to make sure they are notified, like add email addresses of other admins to app.yml?

Also, why get two notifications? This seems new to me.