My LG X Power volume keeps resetting to 2 I turn down my ringer to 0, with no vibrate.  I leave it on my desk, and when I get a message,  I hear the message ding.  When I check, the volume is at 2 (i mean 2 levels higher than vibrate).

This is happening several times a day.  What could be causing it?

I'm using Android 6.0.1
I figured it out.  

It was the "Call Blocker" app from AndroidRock.

The problem went away after I uninstalled the app.  To be sure, I reinstalled it, and the problem came back.  I tried this about 3 or 4 times to confirm.

https://play.google.com/store/apps/details?id=com.androidrocker.callblocker&amp;hl=en