Nexus 6, Marshmallow: Why does MEDIA VOLUME keep turning itself down?

[AC Question]

All updates installed, running Bitdefender Total Security 2016, scans all clean. WITHOUT CHANGING _ANY_ SETTINGS, the volume in "Settings > Sounds and notifications > Media Volume" keeps turning itself down. Usually WAY down, and sometimes even all the way down to "0". The only common denominator is it usually only happens when I hit the "HOME" button, or turn the screen off. NOT the power "off", and _no_, I am not pressing the volume keys by mistake. Besides, the "Ringer" and "Alarm" volume settings NEVER change when the "Media volume" _does_ change (all on its own). frustrated. Yeah, certainly not the worst problem to have (just up the volume again), but annoying as allgetout just the same. Anyone else had this problem and/or ideas on a fix for this?? (and no, I don't want to go the "reset" route for this admittedly minor problem.) THANKS IN ADVANCE FOR ANY AND ALL HELP.

 

[TenshiNo]

I have seen a couple of apps (usually games) which have a "Volume" slider in the settings for the app, that are *really* just turning the phone's media volume up and down rather than just changing the game's volume. Try and determine if this happens immediately after using a specific app, and check for a volume setting in that app.