This is resulting in build failures for epel10 packages (https://pagure.io/releng/issue/12305) and no doubt other issues too.

 
The packages are there, but missing from primary.xml. Current of CentOS-Stream-10-20240903.0 compose is https://mirror.stream.centos.org/10-stream/BaseOS/x86_64/os/repodata/12892a4b1a9c46b2b8fda44f7f88bdac42e9275a6e4b47ae4139cd0285e7451b-primary.xml.gz which indeed lists only shim packages, while the previous one https://mirror.stream.centos.org/10-stream/BaseOS/x86_64/os/repodata/dbedd16f568573ca066246419abcdf059534329c1eb80d857e6d9713a27501a3-primary.xml.gz is all right.

Did merging secureboot-signed packages and normal packages fail?