@TeamYouTube notifications are still not fixed, this is getting frustrating. I’m signed into my other channel I have with my fiancé and I have notifications on for my main channel but no notification showed up at all, I have to reupload the video so hoping it’ll work this time..
You'll want to check account, device, and channel notification settings. Here's a troubleshooter with the exact steps: https://goo.gl/giVA8o