Apt-Cacher-NG did not work - 404 Error

I’ve installed the apt-cacher-ng package from UCS. But with a lot of packages i get an 404 Error.

...
1597010275|I|326|2001:470:1f0b:569:6d9e:25e0:6986:6d30|uburep/pool/main/p/patch/patch_2.7.6-6_amd64.deb [HTTP error, code: 404]
1597010275|E|236|2001:470:1f0b:569:6d9e:25e0:6986:6d30|uburep/pool/main/p/patch/patch_2.7.6-6_amd64.deb [HTTP error, code: 404]
1597010275|I|326|2001:470:1f0b:569:6d9e:25e0:6986:6d30|uburep/pool/main/z/zsh/zsh_5.8-3ubuntu1_amd64.deb [HTTP error, code: 404]
1597010275|E|237|2001:470:1f0b:569:6d9e:25e0:6986:6d30|uburep/pool/main/z/zsh/zsh_5.8-3ubuntu1_amd64.deb [HTTP error, code: 404]
...

An Gentoo in the same network with apt-cacher-ng made the job for many years. The config is the same. But on UCS i get this strange 404 Error. Can anyone help me to solve this? We would delete all us gentoo’s, to only to the job with UCS machines.

Here is my apt-cacher Configfile:

CacheDir: /home/apt-cacher-ng
LogDir: /var/log/apt-cacher-ng
SupportDir: /usr/lib/apt-cacher-ng
Remap-debrep: file:deb_mirror*.gz /debian ; file:backends_debian # Debian Archives
Remap-uburep: file:ubuntu_mirrors /ubuntu ; file:backends_ubuntu # Ubuntu Archives
Remap-cygwin: file:cygwin_mirrors /cygwin # ; file:backends_cygwin # incomplete, please create this file or specify preferred mirrors here
Remap-sfnet:  file:sfnet_mirrors # ; file:backends_sfnet # incomplete, please create this file or specify preferred mirrors here
Remap-alxrep: file:archlx_mirrors /archlinux # ; file:backend_archlx # Arch Linux
Remap-fedora: file:fedora_mirrors # Fedora Linux
Remap-epel:   file:epel_mirrors # Fedora EPEL
Remap-slrep:  file:sl_mirrors # Scientific Linux
Remap-gentoo: file:gentoo_mirrors.gz /gentoo ; file:backends_gentoo # Gentoo Archives
ReportPage: acng-report.html
ForceManaged: 0
ExThreshold: 10
Debug:3
LocalDirs: acng-doc /usr/share/doc/apt-cacher-ng
PassThroughPattern: .* # this would allow CONNECT to everything

Changed back to Squid-deb-Proxy.