After digging in to this issue, I found, I have two slightly different ruby versions on the system:
root@icc-ticket:/opt/zammad# l vendor/bundle/ruby/3.1.0/
total 184
drwxr-xr-x 2 zammad zammad 4096 Dec 8 18:04 bin
drwxr-xr-x 2 zammad zammad 4096 Mar 14 2023 build_info
drwxr-xr-x 3 zammad zammad 4096 Apr 8 2023 bundler
-rw-r--r-- 1 zammad zammad 101749 Sep 13 07:58 compile.log
drwxr-xr-x 3 zammad zammad 4096 Jul 16 10:57 doc
drwxr-xr-x 3 zammad zammad 4096 Apr 8 2023 extensions
drwxr-xr-x 221 zammad zammad 16384 Dec 8 17:48 gems
drwxr-xr-x 2 zammad zammad 4096 Dec 8 18:04 plugins
drwxr-xr-x 2 zammad zammad 40960 Dec 8 18:04 specifications
root@icc-ticket:/opt/zammad# l vendor/ruby-3.1.3/
total 128
drwxr-xr-x 2 zammad zammad 4096 Dec 8 18:04 bin
-rw-r--r-- 1 zammad zammad 113990 Jul 5 11:34 compile.log
drwxr-xr-x 3 zammad zammad 4096 Dec 8 18:04 include
drwxr-xr-x 5 zammad zammad 4096 Dec 8 18:04 lib
drwxr-xr-x 4 zammad zammad 4096 Apr 8 2023 share
root@icc-ticket:/opt/zammad#
Ruby 3.1.0 and Ruby 3.1.3, which is the correct version for Zammad?
