We have enabled the Build fork PRs (merged with base branch) option in our Job for the Github organisation we have, however, when we create a pull request based from a fork, no build is triggered.

This seems to be caused by the hook settings, which are just Push and Repository. Push doesn't seem to trigger when the PR is created, and as such the build is never created from the PR.

When we add the Pull Request event in our github configuration, there build is created correctly.