Can't create second merge request and branch inside issue for other branch than master

GitLab version: GitLab Community Edition 11.11.2 (gitlab-ce@0da38977aca7df3071a936115a7336081b86e4c7)

Steps to reproduce:

  1. Create NEW branch, test branch for example.
  2. Create new issue, Can't create second pull request for issue as example
  3. From issue click on "Create merge request"
    Choose "Create merge request and branch"
    By default branch name will be "1-can-t-create-second-pull-request-for-issue".
    Select test branch as source branch
    Hit "Create merge request" button. New PR and branch is created successfully.
  4. From same issue create new PR and new Branch. Choose "Create merge request and branch"
    By default branch name will be "1-can-t-create-second-pull-request-for-issue-2".
    Select test branch as source branch
    Hit "Create merge request" button. Message Failed to create Merge Request. Please try again. will be displayed. image

With browser debugger open I have seen that request fails. image

Query parameters image

I guess that is not working because query parameters contain old branch name instead of new filled one.