Why does my ringtone choice (in Settings) disappear (V5.1 S4 GPE)?

[Phil Riker]

This has been happening since I got v5.1. I set it and have no idea when or how or why the setting reverts to blank!

 

[B. Diddy]

Welcome to Android Central! Do you mean that after you select a ringtone, some time later it changes to None or Silent? Are these preinstalled ringtones, or custom ringtones that you copied to the phone? If the latter, are they saved to Internal Storage or the microSD card?