Project's members are LDAP Guest and appears as Approvers in Merge Request while project's settings defined no Approvers

GitLab EE version 11.7.0-ee - gitlab-ee-11.7.0-ee.0.el6.x86_64

Context

• LDAP synchro active on group Mygroup : Group: AdminGitlab as Owner on LDAP server
• LDAP synchro active on subgroup mysubgroup_myprj : cn: ldapgroup_myprj with Guest access
• Project name : myprj_toto
• Project path : <srv_name>/Mygroup/mysubgroup_myprj/myprj_toto
• Project members : inherited from Mygroup (Owners) and from mysubgroup_myprj (Guest) + two members added directly at project level
• Project settings for "MR approvals" : no approvers defined and one approvals required and ticked 'Remove all approvals in a MR when...'
• Project settings for "Merge request" : FF merge / description present / ticked 'Only allow...' and 'Show link...'

Issue Scenario From project's "Merge Requests" left-hand side menu (http://<srv_name>/Mygroup/mysubgroup_myprj/myprj_toto/merge_requests) I open a MR using the button "New merge request". It opens the Merge request config for source branch and target branch. Once the branches chosen I click the button "Compare branches an continue". Then it opens the "New Merge Request" page. In this page, whereas no Approvers have been defined at project level config, I get the two last LDAP Guest members in the project's Members list appearing as Approvers of this merge request. Whe should see no Approvers. Which is not normal as:

• no Approvers defined at project level
• the two members appearing as Approvers are only Guests (LDAP) on the project.

Thanks for considering this issue.