Gnome doesn't update sound output device properly
I run Ubuntu 18.10 with Gnome 3.30.1 on an Dell XPS 9370.
If I have music playing (via the built-in speakers) and connect my docking station (a Dell WD15) the music automatically transitions to the speakers connected to the dock (it has a line-out output). The problem is, that Gnome does not recognize that: Even if Gnome shows the line-out output in the sound devices overview, it still has the built-in speakers selected (see attached image) and the multimedia keys still adjust the built-in speaker.