The "Build Current Patches Only" feature currently identifies previous builds based on their parameters as they were present when the build was first scheduled.

If you use a plugin that alters the parameters after the job has started, the cancelling of previous builds does not work, since the GerritTrigger#cancelJob() method does not find the job anymore.

This is easily and trivially fixed, by not scanning for the parameters, but instead for the GerritEvent that is stored in the GerritCause used to start a build.

A pull request has been uploaded here: https://github.com/jenkinsci/gerrit-trigger-plugin/pull/195