Bug while assigning milestone to issue

Summary

Whenever I try to edit an issue through the API it ignores my modification in relation with the milestone.

Steps to reproduce

Just create a milestone and an issue and try the following command:

curl --request PUT --header "PRIVATE-TOKEN: yourToken" http://yourip/api/v4/projects/idproject/issues/idissue?weight=4&milestone_id=idmilestone

What is the current bug behavior?

The response show no change on milestone and neither does the Gitlab client.

{"id":99,"iid":68,"project_id":3,"title":"title","description":"desc","state":"opened","created_at":"2009-05-25T15:22:41.000Z","updated_at":"2017-09-15T13:24:59.361Z","labels":["build_S"],"milestone":null,"assignees":[],"author":{"name":"Administrator","username":"root","id":1,"state":"active","avatar_url":"http://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80&d=identicon","web_url":"http://gitlab.example.com/root"},"assignee":null,"user_notes_count":0,"upvotes":0,"downvotes":0,"due_date":null,"confidential":false,"weight":4,"web_url":"http://gitlab.example.com/root/aa1/issues/68","subscribed":true}

What is the expected correct behavior?

You should see the issue with the correct milestone