Further update. Before I provide additional information, when I test Zorin 17 in live mode it produces sound but wrongly identifies the source as S/PDIF! I have had some issues with PCLinuxOS KDE (running Q4OS instead of Trinity Desktop of PCLinuxOS). Changed to PCIE Slot 1. PCLinuxOS has been pushing out Pipewire updates that did not help my situation, leaving me with sound coming from front centre speaker/s. The solution? Well first make sure you have most of the ALSA packages installed. Then to solve the issue I used Audacious!
Open Audacious and select Output from the Menu Bar, then Audio Settings:
Then click on the ALSA Settings (Output plugin default is Pipewire, followed by Pulse Audio - so I selected ALSA), then used these Settings for ALSA:
PCM device:
Then select this for Mixer Device:
And currently listening to my latest purchase in full surround sound! Yay!:
Favourite track, 2. Restored! No pun intended!