Perhaps you can create a bootable USB stick with Ubuntu 18.04.4 or upwards.
I agree. That's a good reference point to start with.
Additionally try to access your BIOS / EFI menu. Maybe you'll find some tweaks there.
Usually missing sound will not stop video playback on LE.
Hardware specs are interesting for me. I remember a user with a really tiny PC, and CPU performance mode was BIOS-blocked to avoid heat issues. Tiny PC's often want to switch to performance mode after some seconds of video playback, like described here.
On most Linux flavors libdvdcss isn't part of the system due to a missing license. You maybe have to download it manually, and put it into the right folder.
I did a minimal image ubuntu install and now running kodi as a service with no WM. Solid so far and with the added bonus of proper sound again.
That's a proof of my theory. I think it's a timing issue. The more processing the PC has to deal with, the longer the USB latency. At some cutting point, some audio data will be dropped, because there is no chance to deliver in time.
I'm currently running a real-time-kernel Ubuntu for music production with a connected USB-MIDI controller. The USB latency difference between a real-time / non-real-time system is significant. I know what I'm talking about.
-> Stay away from high speed USB audio if you run a regular (non-real-time-kernel) Linux.
My theory: You had a power outage, which turned on your TV by a CEC signal that came from the RPi. The power outage was leading to a bad HDMI handshake, resulting in a wrong HDMI mode.
Things you could do to avoid such situation:
PS: It's like in that "Poltergeist" movie. 
I've never seen such an error in this forum. Is it a reproducible error? If yes, describe all steps you did.
That's great, Denis! Another laptop stays alive. 
You can mark the thread as solved now.
RPi and PC are both USB host devices. You want to use your RPi in USB client mode, but that's impossible.
Blacklist the nouveau driver like this:
APPEND boot=UUID=<YOUR_BOOT_UUID> disk=UUID=<YOUR_DISK_UUID> quiet initcall_blacklist=nouveauIf this doesn't work, try nouveau_init instead of nouveau at the append line.
It's not tested by me, I'm just an RPi user.
PS: Can you post the output of "lsmod" when you're logged in by SSH on LE?
This forum is named "Bug Reports", and that's what I did: report a bug.
It's not against the rules to post it here, but personally I would call it a development discussion, which has an own sub-forum.
Development builds usually have bugs. You can use a stable built.
Do you use the right config.txt option?
"Switchable Graphics" doesn't enforces iGPU usage, so it doesn't help.
Maybe chewitt can explain whether the "nouveau" driver has to be blacklisted, or if there is no need to do that, because the driver doesn't exist on LE. I'm asking because setting the eGPU driver on the blacklist usually enforces iGPU usage.
Yes, disable the eGPU in BIOS. You have a good chance to run LE with the iGPU.
That's the relevant driver modules on Ubuntu:
video 49152 3 dell_wmi,dell_laptop,nouveau
Try to load the "nouveau" driver on LE. My research says the driver has issues with Kodi, so it's probably not available on LE for good reasons.
PS: If "nouveau" isn't on LE, it could be a good idea to stay with Ubuntu. When you autostart Kodi on it, you maybe have all you need.
He came from this thread where he said it's OK on Raspbian Buster. I think it's about internal WiFi, because he didn't mentioned an adapter.
