See this link, where I’ve mentioned before about the docker library link problem:
Therefore for pulling images, rather than attempting to use the shortcut (library) link, just do:
docker pull rockylinux/rockylinux:<tag>
replacing <tag> with 9.6 for example. Obviously that won’t solve your reposync problem, as that is something else entirely. But if reposyinc is using 9 instead of 9.5 or 9.6 which is symlinked to 9, then that would explain why it overwrote what you had synced previously.