Pipeline not triggered on open Pull Request (Bitbucket Server)

Using these settings on drone/drone:1.1, the Pipeline is triggered when the pull request is made but not when additional commits has been pushed.

kind: pipeline
name: default

      - master
      - staging
      - production

When I try removing the trigger block it runs the pipeline normally.

This is a Bitbucket Server issue. They do not send pull_request webhooks when new code is pushed to an existing pull request (i.e. pull request synchronization events). See https://jira.atlassian.com/browse/BSERV-10279

Oh I see, so the temporary work around would be just to trigger the pipeline on push instead of pull_request. Thanks!