Port volumes not remembered when using pipewire

Summary

Headphone/speaker volumes are not separately retained when pipewire is running. i.e. if headphones were previously at 20% and speakers at 40%, plugging headphones in will keep the volume at 40% rather than restore the 20%. Running pulseaudio without pipewire will properly restore volume levels as expected.

environment

Arch Linux Pulseaudio hash pulseaudio/pulseaudio@a6ade6b0

Steps to reproduce

1. Ensure a pipewire session is running
2. Set speaker volume to 40%
3. Plug in headphones
4. Adjust volume to 20%
5. Unplug headphones

What is the current bug behavior?

Volume remains at 20% rather than getting restored to 40%

What is the expected correct behavior?

Volume is restored to 40%