@pewdiepie why did @TeamYouTube turn off your notification, I have my bell turned on from your channel, you get monetized videos yet no notification for your subscribers? Hmmmmmm....
Could you check if you've opted-in to receive all notifications? You may be on the default setting, which is to receive notifications occasionally. Here's a guide to help check that plus your app and device level settings: https://goo.gl/giVA8o . Hope this helps.