When there are 2 or more global libraries P4Jenkins will use the same SyncID for both. This causes polling to always find a change even when no change has occurred.
(1) Under Manage Jenkins add two Helix based Libraries called 'my-shared-library' (org.foo.lib) and 'my-shared-library2' (org.bar.lib).
(2) Create a Jenkinsfile that includes both libraries and uses one of them. For example:
(3) Create a pipeline job that uses the above Jenkinsfile and uses polling as the build trigger.
(4) Manually run the build.
(5) Wait for each poll interval.
Result: A build is triggered for every poll.
Expected Result: Only a change submitted to the libraries after step (4) should cause a poll to trigger a build.