Pull mirroring does not import pull requests

Summary

Hello,

I'm trying to setup Pull/push mirroring by following this documentation : https://docs.gitlab.com/ee/ci/ci_cd_for_external_repos/index.html#connect-to-an-external-repository

Everything working fine, when I go on my project and I enable "Merge Request" I see every merge request imported from my GitHub project, but my problem comes from new pull requests done on GitHub which are not created on GitLab.

We are working on migration from GitHub to GitLab, and we need to setup everything in parallel before give up GitHub, but before migrate we need to have a full synchronization to setup our new ci/cd pipelines.

What is the current bug behavior?

Currently, when I create a new Pull request on GitHub in my project which is mirrored on GitLab with GitHub integration enabled, it's not imported to GitLab.

When I check the webhook status, everything is green, there is no error displayed.

I didn't test it, but other feature like comments, status update, etc... May not be up-to-date.

What is the expected correct behavior?

In my mind, the expected behavior is that a repository on GitHub should be entirely replicated and automatically updated to GitLab to have exactly the same thing on both repositories.

Possible fixes

The solution is already able to replicate everything, you may add something to keep Merge request updated (merge request creation, status, new comment, etc...).

/label ~"support request"