[RPi5] HDMI Audio Stopped working

    Dear Brains Trust,
    I have a RPi5 - LibreELEC 12.2.1 (everything stock) connected to a receiver to TV via HDMI. This setup has been running for some years (RPi3->4->5) faultlessly.
    Today the audio stopped working. I rebooted everything to no avail. Now video picture plays ok, CEC is working, just no audio.
    On digging deeper, I noticed in "Settings->system->audio output device" there is only one option "default, Bluetooth Audio(PULSE AUDIO)". From memory there was also an HDMI option? Am I correct, and that's what should be selected. Which seems to have disappeared.
    - Should there be an HDMI option? And how to get it back? Why did it disappear?

    Many thanks for any assistance in advance.

    Boot the board without an SD card connected. On the bottom of the resulting 'bios' like screen it will show EDID as 'OK' or none. If it shows 'OK' then I can't explain the problem. If it shows 'none' then something is not right in the chain between board and the TV; the EDID data on the HDMI connection contains info on HDMI audio capabilities so no EDID data means no audio in Kodi (hence only the BT audio pulse device shows up). TL/DR; check cables and ports and that everything is seated correctly.

    Following your guide, it shows "display: DISP0: HDMI HPD=1 EDID=ok #2 DISP1: HPD=0 EDID=none #0". I assume DISP1 is the 2nd display that's not connected. I'll re burn the SD Card, see if that kicks it back into shape.
    Thanks for your help.

    SOLVED: its a known fault with 12.2.1. RPi5 firmware fails to init HDMI audio.
    FIX:
    Reset the Pi’s firmware and HDMI state.

    1. Power off the Pi
    2. Remove the SD card
    3. Power on the Pi (let it boot to the “no OS” screen)
    4. Power off again
    5. Reinsert SD card
    6. Boot normally

    Then go to "Setting->System->Audio output device" and reselect HDMI device.
    Done. Worked for mine.