Find out why the the pre-commit build is not started when a new patch is available on a Jira

Symptom:

When I upload a new diff/patch file to an OOZIE-XYZ Jira ticket and then push the "Patch available" button the pre-commit build does not start automatically: https://ci-hadoop.apache.org/job/PreCommit-OOZIE-Build

Task:

Find out what causes this and fix the problem.