If you are attempting to update your AOSC OS, or have already experienced trouble downloading packages (wrong sizes and checksums, etc.) - we are aware of this issue, and are working double time to resolve this issue. We have just finished up our (long overdue) Winter update wave, and moving ~10,000 packages triggered some obscure bugs in our package scanning toolkit, p-vector.
rsyncservice 15 minutes before this news, and this should explain why the syncing jobs are failing.
— Mingcong Bai