Since at least a week ago, some newly created build jobs on our Jenkins do not get triggered by our Subversion's post-commit notification. It has worked reliably for all new jobs before that. Existing jobs do not seem to be affected. Some newly created build jobs work fine as well.

The affected build jobs are Pipelines with "Pipeline Script from SCM". Their SVN polling behavior is set to "@monthly". The notification definitely arrives, but Jenkins apparently can't find any matching builds, see the following log snippet:

May 05, 2020 7:12:27 AM FINE hudson.scm.SubversionRepositoryStatus
Change reported to Subversion repository 2014c15a-19c3-4144-bd3a-3a8116d50215 on [personal/kloster/MyProject/SomeFile]
May 05, 2020 7:12:27 AM FINE hudson.scm.SubversionRepositoryStatus
Starting subversion locations checks for all jobs
May 05, 2020 7:12:27 AM FINE hudson.scm.SubversionRepositoryStatus
Ended subversion locations checks for all jobs
May 05, 2020 7:12:27 AM FINE hudson.scm.SubversionRepositoryStatus
No jobs found matching the modified files

At the time of this log entry, there was a job configured with the SVN URL ending in personal/kloster/MyProject.

Sometimes but not always, changing the SVN URL of the affected build job or manually triggering apoll by appending "/polling" to its URL will "repair" the job, making it react to the commit hook properly.

Any advice on how to further investigate the root cause?