GitLab import not associating issues and other items

Summary

Even with an admin account, when doing a GitLab Import, items are not being associated correctly.

Steps to reproduce

1. Export a GitLab project (from GitLab.com).
2. Import the GitLab project tar.gz file (to GitLab.com).
3. Check who is assigned to issues, merge requests, etc.

Discovered when infra did an import on behalf of customer: https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/6657#note_168188556 note on customer's export file: project_old.json is the original and project.json is a stripped username version; in case it's helpful customer has included their import_export.yaml file (GitLab v11.2.8) in related ticket: https://gitlab.zendesk.com/agent/tickets/109965

Example Project

Even comparing just the issues, things are obviously not being associated properly

Issues from the export (internal):

Issues from the import (internal):

Comments are also just leaving a note of the original author:

What is the current bug behavior?

Items are not associated properly.

What is the expected correct behavior?

Items are associated properly

Output of checks

GitLab.com, GitLab Enterprise Edition 11.11.0-rc1-ee ; the customer import was done before rc1, and my example one was done after rc1

Possible fixes

@jameslopez has been working on this and looking to troubleshoot

@leopardm may also have more information as he has been encountering some issues when importing to .com