Keyboard muting isn't universal

I have a speaker group which containts two monitor speakers as well as the default which is just one monitor speaker. When I mute the audio from the keyboard while using an app that uses the multi-speaker group, it correctly mutes. If I then switch to an app that uses the default audio, a tiny bit of sound leaks through. When I goto the Chorus app, I can see that the default speakers are not actually muted, if I click the speaker icon it will mute. But the keyboard control makes you believe it's muted, even though its not fully muted.

Let me know if that's not clear and I can record a video demo.