Resolution
There is a known limitation with the Run conditional plugin when the run conditionals are configured with a lot of conditions . Testing using 40 conditionals with different shell steps the performance of the plugin can be seen when trying to load the job configuration:
Tests have shown the job configuration page to take several minutes to load the job page. It is recommened to switch to either the pipeline plugin, or condensing the run conditionals to not contain as many conditionals.
See JENKINS-30654 for more information.