I'm very happy that you are heal-thy (censored word 
) again. 
Normally any amount of LE audio output channels should be mapped to the right amount of input channels of the target device. LE had a bug on that mapping, but it's hopefully fixed now.
My suggestion is to try the latest LE 10 Beta, because of the mentioned bug fix.
Because H264 / H265 decoding is already hardware accelerated, activating MMAL makes no sense to me.
I think your RPi4 works as it should, if that's what you're asking for. 
To quote RPi4's tech specs:
H.265 (4kp60 decode), H264 (1080p60 decode, 1080p30 encode)
So re-encode to H264 or H265, and you can expect better spooling behavior.
mooncaptain I noticed that your behavior is weird on this forum.
- You do statements, but we expect clear questions.
- You still haven't responded to your first thread, and you already started another thread.
- You are answering to your own statement on this thread.
If you continue to act that way, I will start to delete your posts.
RPi4 can hardware-decode some codecs. If you re-encode your videos to one of those, you might have a benefit in spooling.
Thanks! The current log says a little more, but we are still missing the whole story, because you are at log level 0:
2021-04-15 17:07:52.093 T:733 INFO <general>: Disabled debug logging due to GUI setting. Level 0.Please connect your RPi to your monitor, where it boots. Then activate debug logging at GUI. This will make a HUD appear on top of the screen. This will increase the log level, and we get more info to help you.
Then switch off, connect to your TV and try to boot. If you have a chance to login by SSH, do so and run pastekodi to get the link to kodi.log. Otherwise read the kodi.log from microSD on your PC.
salvador Please post again in English language, or edit your post that way. This is an English-only forum.
The logs don't say much.
Try to boot the RPi4 just with the TV attached (no keyboard, no mouse, no dongles etc.).
Can you confirm that you never needed custom settings at config.txt to make your TV work on former LE versions?
I think it's an HDMI mode issue. LE 10 Beta 2 does not allow editing HDMI modes at config.txt anymore. Find the best resolution and refresh rate of your TV, and then put it into cmdline.txt. Something like video=HDMI-A-1:1920x1080M@60D. Read here for details: Click!
If you get video signal after this, it would be helpful for us to get a link to a kodi.log. If you did config.txt changes on former LE versions to make your older TV work, please post those settings, too.
I have a issue with my Rpi4. I have updated it to version LibreELEC-RPi4.arm-9.95.2 because I had issue on downloading subtitles.
The release note says: Do not upgrade. Do a fresh install on microSD.
jrousek Is it a fresh installation? Remember, the release note says: Do not upgrade.
I never did this. In theory you should be able to switch to a custom skin, and then overwrite all related menu elements by empty elements.
Please always use our search function before opening a new thread. Go to the forums main page first to search at all sub-forums. Then click the magnifier icon on top.
We already have many threads about the Argon One case: Click!
PRESS This is not the topic of our forum. Use an internet search engine. Moved to Off-Topic.
Better play some re-sampled audio before you take the log.
The dev also mentioned you could try Raspberry Pi OS. Then we get a hint whether it's the USB controller of the RPi4B.
I'm stepping in the dark. 
An audio sync error happens two times, so it could be the cause:
2021-04-20 22:08:12.592 T:779 DEBUG <general>: ActiveAE::SyncStream - average error of 22.197880, start adjusting
2021-04-20 22:08:12.592 T:779 DEBUG <general>: ActiveAE::SyncStream - average error 0.197880 below threshold of 30.000000Try this:
The dev needs a complete log (RPi4 log at post #7 is incomplete). So please activate debugging at GUI (HUD will appear on top), reboot, login by SSH, execute pastekodi (wait...) and post the resulting link. Then we have a complete log. Thanks!