July 2021, Im having the same problem as the OP. I thought perhaps best not to open a new thread and go through all this again. Just to say Im a novice LibreElec user and just installed it. I have limited experience with Rpi and hate trying to do anything at all to my router.
I think I will struggle to connect Ethernet due to location of router and equipment.
I read though most of the above but got a little lost in places where probably people understood more how to get to where they were being directed.
No reply to the other post…
May try changing channel but I can’t see the significance as pi4 was working with libreelec.
On the Rpi forum I got some feedback saying 8 Gb model chip has different power requirements and other distros need updating.