We have jobs of type (1)
• Build whenever a SNAPSHOT dependency is build : NO
• Disable triggering of downstream projects : YES
and jobs of type (2)
• Build whenever a SNAPSHOT dependency is build : YES
• Disable triggering of downstream projects : NO
So jobs of type (2) should not be included in the Jenkins dependency graph. However, they are!

Therefore, we suggest the following patch (https://github.com/jenkinsci/maven-plugin/blob/master/src/main/java/hudson/maven/MavenModule.java), Line 504:

if(!m.isBuildable()) continue;

should be instead:

if(!m.isBuildable() || m.getParent().isDisableTriggerDownstreamProjects()) continue;

The patch has been tested.