Cannot move sub-group to another subgroup

Summary

(Summarize the bug encountered concisely)

Steps to reproduce

1. Have 3 subgroups:

• https://gitlab.com/gitlab-org
• https://gitlab.com/gitlab-org/subgroup-1
• https://gitlab.com/gitlab-org/subgroup-2

1. I am the owner of https://gitlab.com/gitlab-org, but not explicitly any of its subgroup (but still, owner permission is inherited)
2. Try to move https://gitlab.com/gitlab-org/subgroup-2 into https://gitlab.com/gitlab-org/subgroup-1 such that we have https://gitlab.com/gitlab-org/subgroup-1/subgroup-2

(What actually happens)

I cannot choose https://gitlab.com/gitlab-org/subgroup-1 as the parent group, only https://gitlab.com/gitlab-org is display

(What you should see instead)

I should be able to choose https://gitlab.com/gitlab-org/subgroup-1/ as the parent group

Results of GitLab environment info

Gitlag 11.8.0-ee https://gitlab.inspectorio.com/help?nav_source=navbar

Possible fixes

I cannot assign myself as owner of https://gitlab.com/gitlab-org/subgroup-1 and/or https://gitlab.com/gitlab-org/subgroup-2 either, but if I use another account and explicitly assign that account to be owner of both these group, I can choose https://gitlab.com/gitlab-org/subgroup-1 as the parent group