Why won't my Galaxy S4 always mute?

[AC Question]

Galaxy S4 Won't Always Mute

I noticed that sometimes when I have the phone on mute, it's not really muted. The last time this happened, I was on mute while using the headset and I took the headset off. I believe the phone automatically became unmuted and I hit the mute button, but people could still hear me. I don't know if this is always the sequence of steps that leads to my phone not really being on mute.

 

[JC1]

Re: Galaxy S4 Won't Always Mute

My Android version is 5.0.1