Ringtone keeps going off but no one is calling, how to fix?

[Rossy95]

I've just done the new update like a day ago and since then my ringtone just goes off randomly and won't go off because no one is calling.  How can i fix this? 

[xSteveuk]

Hi
Check your ringtone
Settings
Sounds and vibration
Ringtone

Also check notifications
You haven't set Ringtone
As a notification sound

[Plcommers3]

Try restarting the phone. It worked for me.