I have a pipeline Job, which is checking out several svn repos.

When this job is run, the changeset reflects the changes. However, it sometimes gets called by a different job (very simple freestyle; we call it the trigger job). Whenever that happens, the changeset of the called job is entirely empty. (If there are changes in the repo where the Jenkinsfile of the called job resides, these changes are in the changeset, but not the changes of any repo the Jenkinsfile checks out.)