Thanks for testing master. There might be something else in your environment that is different than mine, and that is causing the issue.
Just made sure that I had the latest code from master, copied your `config.xml` from this issue description, and replaced my `config.xml`. Reloaded Jenkins.
Successfully filtered the parameter on Firefox and Chromium and Chrome on Ubuntu LTS. See GIFrecord... gif image for a screenshot of the plug-in with your `config.xml`. I have NoScript and uBlock origin enabled in every browser, which normally causes some issues. But these extensions didn't seem to impact the functionality of the plug-in.
Could you check if there isn't another setting that we have different in our environment, ericcitaire ? I have Jenkins 2.263.1 with
Apache Maven 3.8.2 (ea98e05a04480131370aa0c110b8c54cf726c06f)
Maven home: /opt/apache-maven-3.8.2
Java version: 11.0.11, vendor: Ubuntu, runtime: /usr/lib/jvm/java-11-openjdk-amd64
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "5.4.0-89-generic", arch: "amd64", family: "unix"
It's Ubuntu 20.04 LTS, and Firefox 93.0 (build 64).