Users are not automatically added to the default group when using LDAP with local groups permission

Environment

Confluence 5.10.7
Active Directory LDAP

Actual behavior

Confluence does not add the LDAP users inside the local groups when the LDAP is set with the permission, "Read only with local groups" and have the same group name inside the tree.

Steps to replicate

1) Install Confluence 5.10.7
2) Create a Group called Confluence-users in the LDAP
3) Setup Confluence with AD LDAP, read only with local groups and set the default group membership as Confluence-users.
4) Set the internal directory in the first position.
5) Full Sync.
6) Confirm that the LDAP users are inside Confluence and choose one user.
7) Verify that this user is not inside the Confluence-users group.
8) Logout and login as this user.
9) You'll see a not permitted screen, as the user was not present in the Confluence-users group.
10) Login as local administrator confirms that the user is not part of the Confluence-users group.

Expected behavior

Confluence should add the users to the local groups when selected in the LDAP configuration menu.

Workaround

During local testing, when the LDAP is placed on the first position and a new user logins, the user is correctly placed inside the Confluence-users group, so this is the workaround for now.

It seems that the directory order directly activates the bug.