HelloAlarm, car seat belt, radio and other notifications were suddenly muted. Looks like a mute feature has taken effect. Some tips here.

 

Had the same experience one day with my new 2023 XC60. All of the sudden, everything muted- music, sound, even the clicking ot the directional. Tried a few things, like changing settings - still muted....
Later, when I restarted the car, everything seemed to come back.