Update fails with: repomd.xml: [Errno 14] HTTPS Error 403

NethServer Version: 7.9

The current update fails with:

# yum update
Geladene Plugins: changelog, fastestmirror, nethserver_events
Loading mirror speeds from cached hostfile
 * nethforge: markusneuberger.at
 * sb-base: u3.nethserver.com
 * sb-centos-sclo-rh: u3.nethserver.com
 * sb-centos-sclo-sclo: u3.nethserver.com
 * sb-epel: u3.nethserver.com
 * sb-extras: u3.nethserver.com
 * sb-nethserver-base: u3.nethserver.com
 * sb-nethserver-updates: u3.nethserver.com
 * sb-updates: u3.nethserver.com
 * stephdl: stephdl.klinknetz.de
mrmarkuz/7/signature                                                                                                                                           |  490 B  00:00:00     
mrmarkuz/7/signature                                                                                                                                           | 2.9 kB  00:00:00 !!! 
nethforge/7/x86_64/signature                                                                                                                                   |  836 B  00:00:00     
nethforge/7/x86_64/signature                                                                                                                                   | 3.6 kB  00:00:00 !!! 
https://u2.nethserver.com/stable/7.9.2009/base/x86_64/repodata/repomd.xml: [Errno 14] HTTPS Error 403 - Forbidden
Anderer Spiegelserver wird versucht.

<snipped>

failure: repodata/repomd.xml from sb-base: [Errno 256] No more mirrors to try.
https://u2.nethserver.com/stable/7.9.2009/base/x86_64/repodata/repomd.xml: [Errno 14] HTTPS Error 403 - Forbidden
https://u3.nethserver.com/stable/7.9.2009/base/x86_64/repodata/repomd.xml: [Errno 14] HTTPS Error 403 - Forbidden
# 

yum clean all didn’t help

What can I do to fix it?
The mirrors are not block by firewall, IPS and thread shield are not installed.

I can access the sites by my browser: https://u2.nethserver.com/stable/7.9.2009/base/x86_64/repodata/repomd.xml

…but needs credentials:

Sincerely, Marko

I see, an expired subscrition…