I wrote 'LibreELEC (RPi4)' using Imager to an sd card, boot up, pick an 'install from repo' video add-on, play something (CBC Sports - anything) and there's no sound.
While playing the stream, Audio settings shows greyed out text: 'Audi stream Undetermined - AAc etc.'
Then go to system/system and Audio shows greyed out text: Audio output device Default, Bluetooth Audio(PULSEAUDIO)
Hope someone can help - and understand that 'RPi4 and audio' can be a problem. I'm no expert but can follow clear instructions!