procount currently we only have the latest version available, via https://releases.libreelec.tv/noobs/..., but that does seem to cause issues with the mirrors so we are discussing if we should provide versioned directories.
9.2.6 was our last release for RPi1, RPi2 (also used for RPi3), RPi4 and RPi5 releases are at 11.0.5 now - which was just released today and the mirrors don't seem to have picked up the new noobs files yet.
eg https://ftp.halifax.rwth-aachen.de/libreelec/noobs/ doesn't have RPi5 yet but it's available directly from our release server - eg https://releases.libreelec.tv/noobs/LibreELEC_RPi5/os.json, RPi2 is at 11.0.4 (the previous release) and RPi4 at 11.0.3 (I broke RPi4 and RPi5 noobs builds in 11.0.4 so that was our previous RPi4 noobs release as well).
The easiest solution would be if you could pull a json with the latest noobs image metadata from our server, like RPi imager does - then we can automatically update it when we do a new release.
Regarding image metadata: do you have some info which settings should be in the os/os_list.json files`? Currently we fill in lots of very deprecated fields like supported_hex_revisions which IIRC got dropped ages ago and may be missing some other now required fields.
so long,
Hias