issues

/usr/share/apt-cacher/apt-cacher-cleanup.pl -n

deb.debian.org_debian_dists_buster-updates_{In,}Release not available upstream. 
Remove the following files manually if they are no longer significant and you want to clean cached packages they reference:-
  deb.debian.org_debian_dists_buster-updates_main_binary-amd64_Packages.xz
  deb.debian.org_debian_dists_buster-updates_main_source_Sources.xz

rm /var/cache/apt-cacher/packages/deb.debian.org_debian_dists_buster-updates_main_binary-amd64_Packages.*
rm /var/cache/apt-cacher/packages/deb.debian.org_debian_dists_buster-updates_main_source_Sources.*