Flashed an USB-stick with LibreELEC-Generic.x86_64-9.95.1.img.gz (and also LibreELEC-Generic.x86_64-10.0-nightly-20210323-32b3089.img.gz). Both images show the option screen, but can't boot installer, live or run image.
I guess it has something to do with the UEFI-only boot method. Secure boot is disabled. LibreELEC-Generic.x86_64-9.2.6 is able to start (and actually in use on a SDD). Wanted to test the BETA from the USB-stick.