Brief moment of output in headphones when switching between internal speakers and displayport output

• Operating system: Fedora 35 Beta
• Wireplumber version: 0.4.4
• Installed from: Fedora update 0.4.4-2 in testing (but also happens with a local build master branch commit 51713d30)
• Hardware:
  • Computer: Lenovo ThinkPad X230
  • Headset: Jabra UC Voice 150 duo
  • Monitor: HP Z27i

On a laptop with internal speakers and a usb headset and displayport monitor connected, switching between internal speakers and displayport output produce short burst of output in the headset, even though it is never selected as output.

To reproduce:

1. Connect a usb headset and a displayport monitor to a laptop with internal speakers.
2. Start a program that outputs sound
3. Open Gnome Settings, Sound page
4. Ensure that the headphone output is not muted
5. Select internal speakers as the output device
6. Select displayport as the output device

Actual results: There is a very short moment when output is sent to the headphones

Expected results: No sound goes to headphones during the switch.

I gathered logs by running a local build from the master branch commit 51713d30. See separate comment. The lines containing Jabra_UC_VOICE_150 look suspect.