For MultiBranch pipeline, why PR sometime is triggerred by "pull request", and sometimes it is triggerred by "branch indexing"

My checkout repo will failed when branch indexing event trigger the Pull Request CI, and succeed when pull request event triggerr the Pull Request. that is very strange, how can I configure to make the Pull Request triggerred just by pull request.

The details info can be found from [JENKINS-69178] multiBranch pipeline failed with PR code checkout by GitScm - Jenkins Jira

if anyone kow the reason and please kindly share with me, thanks & regards.

resolved, close this ticket topic

Good to know.
Could you please let us know what the solution to your problem was?