kernel-preempt-devel

[arvidjaar]

@averageStudent

~ > sudo zypper lr -d
#  | Alias                                                  | Name                                                                                        | Enabled | GPG Check | Refresh | Priority | Type   | URI                                                                          | Service
---+--------------------------------------------------------+---------------------------------------------------------------------------------------------+---------+-----------+---------+----------+--------+------------------------------------------------------------------------------+--------
...
11 | repo-oss                                               | Main Repository                                                                             | Yes     | (r ) Yes  | Yes     |    1     | rpm-md | http://download.opensuse.org/distribution/leap/15.4/repo/oss/                | 
...
13 | repo-sle-update                                        | Update repository with updates from SUSE Linux Enterprise 15                                | Yes     | (r ) Yes  | Yes     |    4     | rpm-md | http://download.opensuse.org/update/leap/15.4/sle/                           | 
...

My best guess is that due to non-standard priorities (main repository has the highest priority) zypper prefers packages from the main repository over packages from the update repository. So it does not install available updates and when doing dup it offers to downgrade to packages from the main repository.