Notification Sound Keeps Turning Off?

[desktop]

My friend has a Kyocera Hydro with Boost and for some bizarre reason his message notification sound keeps turning off. I checked all his settings including the ones for Messages and made sure they were set correctly, but it still wasn't making any sound when he received text messages. So I did a factory reset, checked all the message and phone settings again and for a short time it did work, but then it stopped again.

I haven't been able to figure this out so I thought I would post and ask the Android community for any suggestions.

Thanks