This is just generally how you should restart most things on systemd systems.

Thank you, I added the command to my Linux Journal,

Your post motivated me to do some more trials and it ended up that my greetd greeter was locking up the audio sink.

So I made sure to add a command after the greeter exits killall -u greeter and the sink finally passed correctly to the logged in user just fine after that.

In reviewing the arch wiki some more too I've installed wire plumber session manager for pipewire, I am still a little confused about it's function and relation to pipewire but maybe that has helped too?

Cheers :)

I used to have to occasionally run this but I'd say it has been at least a couple of years since I last had to. I was a pretty early adopter of pipewire because it solved some Bluetooth issues that pulseaudio had. It has improved immensely since I first started using it.