When I am trying to access build.suse.de from Tumbleweed by "osc -A
https://api.suse.de/ ls SUSE:SLFO:Main util-linux". I get:

Server returned an error: HTTP Error 401: Unauthorized

I tried to remove all credentials and configuration files. The same error. I
tried the same with the freshly created local user with empty home. The same
error. I even tried to downgrade to osc-1.9.0. The same error.

If I do the same on openSUSE Leap 15.6 with osc-1.9.0, then it works.

Access to build.opensuse.org works on both.

The problem first appeared after the last zypper dup two weeks ago.