Group milestones are showing 0 issues for sub-group project issues

Summary

Group milestones are showing 0 issues when issues are located inside a sub-groups projects.

Steps to reproduce

• Create a group.
• Add a Group-Milestone inside it.
• Now add a sub-group.
• Add a project inside the sub-group.
• Add an issue inside the project.
• Now set the Group-Milestone we created recently as the selected milestone for this issue.
• Now open the Group-Milestone, you will notice that total issues are zero not one!

Example Project

https://gitlab.com/groups/example8/-/milestones/1

• Please note that this milestone contains one issue actually. https://gitlab.com/groups/example8/-/issues

What is the current bug behavior?

Not counting the issues in group-milestones.

What is the expected correct behavior?

Show the exact number of issues inside the milestone + show the progress.