Sound plays from multiple speakers with slight delay

### Steps to reproduce

I have 2 speakers, the builtin laptop speaker and the speaker built into my monitor.

1. Laptop speaker is default speaker
2. use pavucontrol to set the element call tab to use the monitor speaker
3. go to element settings, set the speaker to the laptop speaker. this spawns a new playback instance in pavucontrol
4. use pavucontrol again to set the tab to use the monitor speaker

### Outcome

#### What did you expect?
pavucontrol and element call stay in sync about what speaker they use

#### What happened instead?

Sound plays from both speakers with slight delay, sounding very 80s.

### Operating system

I use Arch BTW

### Browser information

Firefox 152.0.5

### URL for webapp

call.element.io

### Will you send logs?

Yes

No source file, test, or entry point is named. Start by reproducing the issue on call.element.io with pavucontrol using the listed speaker-switching steps, then inspect the call audio-device selection and playback behavior; done means pavucontrol and Element Call remain on one speaker without delayed duplicate audio.

Written by the indexing model from the issue text.