The Bitbucket APIs were recently changed for GDPR reasons, replacing usernames with UUIDs in many places. There was work to accommodate this change in
However, since these changes, pushes to Bitbucket are failing to trigger Blue-Ocean-created builds in Jenkins.
The root cause seems to be that Blue Ocean populates the build owner with a UUID value in the build configuration. Manually replacing this with a Bitbucket username fixes the problem and triggering works again.
See the attached screenshot of an example problematic configuration, containing a UUID as the owner.