Why 3rd party app notification are not muted?

[fardream]

Any difference between the implementations? Notifications for 3rd party apps will not mute on "vibrate", and (more annoyingly) all other kinds of sound like game sound neither. But looks like 1st party app does mute

 

[philpeeps]

Mine mute just fine when on vibrate. Games/music, etc is a known "feature".