Volume being set to 0 by a ghost?

[t6lock]

I normally have my volume set to 3 bars, I never for any reason mess with it. If anything I use the mute slider. But since I installed iOS 9, I sometimes find my volume is at 0 bars. Mainly when I am opening games (Simpsons Tapped Out and Clash of Clans). Anyone know why this is happening?

 

[t6lock]

Figured it out from an Apple forum. Whatsapp is muting it when you go to the camera app within it. Apparently for Snapchat too.

 

[Pinkpoison]

Thanks for letting us know, It might help someone else.
Glad you got it sorted.