As mentioned, we already had such audio issues. Every non-4K cable has it's own limits. I assume you have pass-through activated at the audio settings. To figure it out on your setup with 4K cables...
Please provide a full debug log.How to post a log (wiki)1. Enable debugging in Settings>System Settings>Logging2. Restart Kodi3. Replicate the problem4. Generate a log URL (do not post/upload logs to the forum)
use "Settings > LibreELEC > System > Paste system logs" or run "pastekodi" over SSH, then post the URL link
use "Settings > LibreELEC > System > Paste system logs" or run "pastekodi" over SSH, then post the URL link