Asking for all sites of groups returns unrealated sites

Question

Expected behavior.

A call to GET https://graph.microsoft.com/v1.0/groups/{group-id}/sites/ should get all sites related to a group, for example those automatically created in msTeams when a private channel is used.

Actual behavior.

Seems to return all sites instead

Steps to reproduce the behavior.

1. Make a team A on MsTeams, post messages with attachments to force create the associated sharepoint site to the group.
2. Then create a private channel on teams A to force the creation of a separate sharepoint site associate to the group.
3. make a new team B and post messages with attachments to force create the associated sharepoint site to the group.
4. call GET https://graph.microsoft.com/v1.0/groups/{group-id}/sites/ with group-ip corresponding to the team A on msTeams.
5. The result is like the screenshot on actual behavior and the site associated to team B appears among others.
6. We would have expected two sites, the root site of A, and the site corresponding to the private channel on team A.

(we got redirected here from our ticket here https://github.com/microsoftgraph/msgraph-sdk-java/issues/1868)