Our Jenkins is running a Master > Agent setup. Builds triggered by a push to one of the configured named branches works okay and the jobs run on the agents. 

However, jobs triggered by a PR request are not being built on the agents, but rather on the master, which is causing issues since our Master node is tiny, not meant to actually build.

The master is configured to have 0 executors at the moment, but its still triggering the PR request build.

Any help would be appreciated.