Here is how it goes.

I turn on the phone. Switch to some user account.
When I press volume up/down button the volume is at lowest and the bell icon is on mute. After raising volume the bell icon is still on mute. And when i press on the bell icon I have vibrate and two mute icons, unmute bell is mute now.

Solution is folowing
Volume up, press 3 dots for all volumes settings, toggle all volumes up down and press mute unmute bell icon.
After that is all normal.

Can anyone else prove this or reproduce?