Group milestone links lead to 404 pages when not on subgroup milestone page

We've recently noticed a 404 error when attempting to access our group milestones when not on our subgroup milestone page.

Examples:

Using the following URL: https://hostname/groups/parentgroup/-/milestones

Clicking a milestone link takes us to: https://hostname/groups/parentgroup/-/milestones/ Which throws a 404.

As opposed to the following URL: https://hostname/groups/parentgroup/subgroup/-/milestones

Clicking a milestone link here takes us to: https://hostname/groups/parentgroup/subgroup/-/milestones/ Which correctly loads the milestone.

Both pages show the same set of milestones, however, clicking on a milestone's link from the former URL throws a 404, while clicking on the link from the latter loads the correct milestone page. I'm not sure if this is a bug or not, but shouldn't both sets of these links go to the same page?

Thank you.