Push mirroring doesn't bring new branches from A to B

Hi

today I have experienced an issue with mirroring feature of Gitlab-CE (v. 11.3.1).

As a maintainer I have 2 repositories A and B

• A has 4 branches: master, user-1_A, user-2_A, user-3_A
• B has 1 branch: master

I have setup mirroring under the setting of repo A. When I click "Update Now" button, A pushes changes from master branch to the master branch of B. This works fine. However I do not get all 3 remaining branches in B. Though I have created these branches also manually under the repo B, the mirroring still doesn't work. I couldn't find any feasible reason that might cause this issue. There is just a small single file in each branch, so no large files as well.

According to the Repository Mirroring documentation my understanding is that new branches should be exposed automatically and push mirroring should work similarly to master branch.

Is this a bug ?

Bests, Seymur