LibreELEC 9.2.2 (Leia) is a Hotfix release just for the x86_64 Generic (PC, AMD, Intel, NVIDIA …) image.
It includes a fix for the missing sound at Intel based systems (mainly NUC) due an Linux Kernel bug.
This is just for the Generic image as the fix only targeting this platform.
On first boot the Kodi media database will be upgraded. Depending on your hardware and media collection size this could take several minutes. Please be patient.