I did an update from 15.2 to 15.3 and now have non-installable patches:

# zypper patch
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12 Problems:
Problem: the to be installed patch:SUSE-2020-3792-1.noarch conflicts with 'gzip.x86_64 < 1.10-4.3.1' provided by the installed gzip-1.10-3.11.1.x86_64
Problem: the to be installed patch:SUSE-2021-510-1.noarch conflicts with 'ucode-intel.x86_64 < 20210216-3.64.1' provided by the installed ucode-intel-20210216-2.19.1.x86_64
Problem: the to be installed patch:SUSE-2021-931-1.noarch conflicts with 'libnghttp2-14.x86_64 < 1.40.0-3.11.1' provided by the installed libnghttp2-14-1.40.0-3.5.1.x86_64
Problem: the to be installed patch:SUSE-2021-1235-1.noarch conflicts with 'numactl.x86_64 < 2.0.14-4.3.1' provided by the installed numactl-2.0.14-1.1.x86_64
Problem: the to be installed patch:SUSE-2021-1499-1.noarch conflicts with 'webkit2gtk-4_0-injected-bundles.x86_64 < 2.32.0-3.74.1' provided by the installed webkit2gtk-4_0-injected-bundles-2.32.0-3.15.1.x86_64
Problem: the installed libx265-192-3.4-pm152.1.2.x86_64 requires 'libnuma.so.1()(64bit)', but this requirement cannot be provided
Problem: the to be installed patch:SUSE-2021-1654-1.noarch conflicts with 'libxml2-tools.x86_64 < 2.9.7-3.34.1' provided by the installed libxml2-tools-2.9.7-3.31.1.x86_64
Problem: the to be installed patch:SUSE-2021-1765-1.noarch conflicts with 'libX11-xcb1.x86_64 < 1.6.5-3.18.1' provided by the installed libX11-xcb1-1.6.5-3.15.1.x86_64
Problem: the to be installed patch:SUSE-2021-1914-1.noarch conflicts with 'libopenmpt0.x86_64 < 0.3.28-2.13.1' provided by the installed libopenmpt0-0.3.19-2.10.1.x86_64
Problem: the to be installed patch:SUSE-2020-3129-1.noarch conflicts with 'sysconfig-netconfig.x86_64 < 0.85.6-3.6.1' provided by the installed sysconfig-netconfig-0.85.6-3.3.1.x86_64
Problem: the to be installed patch:SUSE-2021-1200-1.noarch conflicts with 'libreofficekit.x86_64 < 7.1.2.2-13.15.1' provided by the installed libreofficekit-7.1.2.2-2.3.x86_64
Problem: the to be installed patch:SUSE-2021-1569-1.noarch conflicts with 'libreoffice-writer.x86_64 < 7.1.3.2-13.18.3' provided by the installed libreoffice-writer-7.1.2.2-2.3.x86_64

Problem: the to be installed patch:SUSE-2020-3792-1.noarch conflicts with 'gzip.x86_64 < 1.10-4.3.1' provided by the installed gzip-1.10-3.11.1.x86_64
 Solution 1: Following actions will be done:
  deinstallation of gzip-1.10-3.11.1.x86_64
  deinstallation of plymouth-scripts-0.9.5+git20190908+3abfab2-5.3.x86_64
  deinstallation of suse-module-tools-15.3.6-1.1.x86_64
...