I have an issue currently where if I suspend my laptop connected to my bluetooth headphones, when I resume the volume will jump to max volume everytime.
However, if I leave the laptop on and turn off and reconnect the headphones, it will remember the last volume.
I installed arch using the archinstaller and am running pipewire and wireplumber.
I understood that. I am also using pipewire, but is is just the backend for pulseaudio. Did you strip out PA completely? I suggested restarting it because PA can be weird after resuming from suspend.