The JaCoCo plugin is displaying empty coverage reports with the current plugin parent pom.
According to this issue JENKINS-28652 maven plugin should be updated to >0.7.5 to fix the issue.
Code changed in jenkins
User: Oleg Nenashev
Merge pull request #52 from alvarolobato/master
JENKINS-42800 - Bump JaCoCo version to be compatible with Jenkins JaCoCo plugin data format
The fix has been released in plugin-pom 2.25