After upgrading pipewire to 0.3.72-1, after sleeping the computer and waking it up I no longer have HDMI audio until a restart the computer again.
Downgrading back to pipewire 0.3.71-2 resolved the issue so seems something in the new version is broken.
OS: Manjaro Linux x86_64
Host: X570 AORUS ELITE -CF
Packages: 1528 (pacman)
CPU: AMD Ryzen 9 5950X (32) @ 3.400GHz
GPU: AMD ATI Radeon RX 5600 OEM/5600 XT / 5700/5700 XT
Memory: 10701MiB / 64224MiB