made it so far that I now know the problem is actually :
No sound in Chrome...ALMOST solved - Add-on Support - LibreELEC Forum
when opening the youtube page, it somehow activates the audio, after that I can use the browser plugin normally.
What I am now looking for is a command that I can put into the chrome-start script that will force it to activate.
Any ideas anyone? 
I'm having some chrome sound issues too. After putting in the custom audio device and then adding it into chrome-start script with the nano command, I now realized it is working fine if I first go to youtube. Somehow this activates the audio. So in the end, it wasn't a setting issue, but it was actually the problem you described here.
Any update on progress on this?
I'm having the exact same issue. Only with me it's also with a fresh install. Any idea what it could have been?
this issue sounds like it could be very similar
Going to to try to add this manually. Don't know why this post didn't come up earlier in my search. It could be that the settings are not updated to the start script. I'm using libreelec on a x86 system. Maybe different folder?
Ah, did not know. My apologies. I thought you just could not get support when asking about these. Not when one of these banned add-ons where installed on your system. Thank you for the heads up.
Doesn't change the fact that my issue is purely about the supported chrome add on though.
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Mar 12 15:03:50.870935 LibreELEC kodi.sh[1397]: [1539:1539:0312/150350.870790:ERROR:alsa_util.cc(204)] PcmOpen: plughw:1,9,Device or resource busy
Mar 12 15:03:51.829820 LibreELEC kodi.sh[1397]: [1396:1418:0312/150351.829581:ERROR:bus.cc(393)] Failed to connect to the bus: Could not parse server address: Unknown address type (examples of valid types are "tcp" and on UNIX "unix")Thanks for the reply Da Flex,
I didn't read the post but have read it now. Not sure if this is applicable to my problem though. output of amixer tells me that auto mute is not turned on. Maybe I am missing something?
Using audio over HDMI, I have always used the Chrome add-on to much succes. Now I can't get it to work anymore with audio!
I'm using a custom audio device using the line "ALSA:plughw:1,9"
This is based on aplay -L shown below
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC887-VD Analog [ALC887-VD Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 1: ALC887-VD Digital [ALC887-VD Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: HDMI [HDA ATI HDMI], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: HDMI [HDA ATI HDMI], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: HDMI [HDA ATI HDMI], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: HDMI [HDA ATI HDMI], device 9: HDMI 3 [HDMI 3]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: HDMI [HDA ATI HDMI], device 10: HDMI 4 [HDMI 4]
Subdevices: 1/1
Subdevice #0: subdevice #0
To be sure, I have used all combinations from 0,1 to 1,10
Reading other threads on the forum I can't see what's wrong with my setup.
Any idea what I am doing wrong?
Kind regards,
Joris