Maybe...but when I go to the Whitelist settings, 3480x2160 60hz is no longer available there -- even though the 4k 60hz setting stayed selected in the main display settings menu.
I think the whitelist is loading HDMI modes from currently available displays, but the older EDID is still in use. Probably your AVR is old, and has a problem with 4K modes.
Then, I reconnected the Pi through the receiver, as per normal. The refresh rate stayed at 60hz, even across a boot. It disappeared as an option in the Whitelist settings, but that doesn't seem to have mattered. (Unless Kodi is showing 60hz, but really using 30hz....?)
Theory: Your EDID was updated during your direct RPi - TV connection. Now your current RPi - AVR - TV setup keeps that setting.
I wanted to run chrome
Chrome is only available on Generic-legacy, because it needs X11 as display server.
Yes, the Intel J4105 HTPC seems to work with LE:
Read the rest of that thread for pros & cons, as well as other hardware recommendations.
@gizmomelb If the user just wants more codecs, and less trouble, then my answer is right. Kodi runs as an app on Nvidia Shield.
NUC --HDMI--> LG TV --OPTICAL--> LG compact home theater system
The optical TOSLINK and/or the TV is the bottle neck here. TOSLINK is too slow for EAC3, but HDMI can handle it.
I have to ask how I can find the log..
We prefer to get a copy on our log server, which saves storage space here. If you have SSH access, you can activate log level 1 by creating an advancedsettings.xml. Then reboot, run pastekodi from SSH, and post the resulting URL.
Will I have any chance installing an older version?
Let us see the log from latest LE 12 Generic-legacy first.
Is it safe to use built-in kodi commands (Powerdown) to shutdown the device?
Yes. The most important part is unmounting devices, which shutdown / poweroff commands do.
This is precisely what I am currently using, RPI 4B, i thought I could take advantage of these boxes which cost half price !
In that case, Nvidia Shield would be the right upgrade, but it's more expansive.
Make a backup, and try to update. We don't have a GPU whitelist.
Pretty new hardware, so try the latest LE 13 nightly build.
Just put the release build (img.gz file) into /storage/.update, and reboot.
You can use wget to download the file from SSH.
If you're a nerd, make a backup first.
Piracy logic - not our turf. 
I bet you have at least one banned add-on installed. So nice to see such warnings. 
Uninstall all banned add-ons and repos.
Any recommendations what I could try next?
Can you read the FAT partition on your desktop PC? If yes, then maybe your RPi card reader is broken.
LE has many default settings for different remotes included. Some of them are outdated for some buttons.
