Help Ringtone doesn't change when I change it

[koterasti]

On a Galaxy Note phone.
Trying to change ringtone.

I can choose any ringtone but when I receive a standard call it uses the "Quantum bell" ringtone no matter what I have chosen.

When receiving a Viber call however, it uses the ringtone that I have chosen. In Viber settings I have selected "use system sounds".

I suspect that something is overriding my chosen ringtone but I've no idea where or how to fix it.

 

[koterasti]

Rebooting the phone seems to have solved this problem.

Still no idea what caused it.