my setup:
i have 2 displays, which one of them is a normal computer monitor (dp) and the other is a small tv via (hdmi).
I use an external soundcard/Headphone Amplifier via usb wich works fine
and the tv runs parallel via hdmi video and sound (so i can watch some movies while browsing).
Its seems Pulse Audio Volume Control names things other then what it is.
My TV is at hdmi1
in pvacontrol (still using piprewire)
you have to set it (under configuration tab) to “Digital Stereo (HDMI 2) Output”
make sure to set the volume control to 100% in the output tab
make sure to choose your correct audio source in the playback tab
in the end it seems pvacontrol is switching settings automaticly and at random when not used,
after restart or sometimes after just pausing a show.
For image number 2, you are pointing to HDMI 2, but the checkmark (the currently used device) is Fiio E10 Analog Stereo.
That checkmark determines which device is used for playback. The Playback tab only shows the source of the playback (a media player, web browser, etc.).
So, no matter how high the volume on a device is, it is muted if the checkmark for it is not selected.