Colon in URL off proxied yum repository doesn't work

hi,

to install cri-o as container runtime for kubernetes in our production infrastructure I need to proxy the yum repositroy /repositories/devel:/kubic:/libcontainers: - openSUSE Download
but i get an 502 error code when i try yum update

"yum update
devel:kubic:libcontainers:stable:cri-o:1.27 (CentOS_8) 28 kB/s | 1.8 kB 00:00
Errors during downloading metadata for repository ‘SVP-devel_kubic_libcontainers_stable_cri-o_1.27’:

error message in nexus.log is
“org.apache.http.client.ClientProtocolException: URI does not specify a valid host name: stable:/cri-o:/1.27/CentOS_8/repodata/repomd.xml”

I guess the colon in the url are the reason, and nexus can’t handle it. Does anyboady know a workaround?

thanks and best regards