KUbuntu 15.04, headphones no longer mute laptop speakers

In 14.04 and 14.10 I could plug in my headphones and my laptop's speakers would be muted. At the very least audio would be directed to the headphones and I could manually mute the speakers via the tray icon. However in 15.04 this behavior no longer occurs. To switch between the speakers and headphones I need to enter System Settings and adjust the output manually.

I'd like to think this is me botching the configuration somewhere but believe it to be a bug. Looking for confirmation before submitting a bug report as I did not see one on Launchpad.

FWIW this is with 15.04 updated last on 03/24ish? Installing the latest round as I write this (3/26).