Default notification sound changed with update ?

[DotsFar]

My wife's phone has started using a new default notification sound for e.g. screen lock/unlock and play store notifications.

The strange thing is both screen lock/unlock and play app settings are to use the default sound, but that is not the sound it makes...

Any one have an idea how this happened and how to get it under control ? Changing the default sound to something else in settings doesn't help, which makes sense as apparently it plays another sound than what is in this setting...

Best regards
Dennis