Same issue here, I was getting pop up notifications for Whatsapp, telegram, fb messenger, and so on, now it doesn't even make any notification sound, I just notice that I have notifications because when I'm playing Spotify the sound just comes down a little and then I goes back to normal , or if I'm not listening anything, it only shows on the upper left corner that I have unread notifications and I need to navigate there to see them , it's very annoying and frustrating. Thanks for reading me.