[xwiki-users] Multiple entries of an user are created in group.

In Xwiki when we use xwiki.authentication.ldap.mode_group_sync as always then on each login by a single user, multiple entries are created in group. So when we delete user entry from LDAP group its not affecting in XWIKI as it has multiple entries in group. So can anyone please help me to solve this issue. When we change option to create this issue is not there but this option we don’t need as it will not update LDAP group changes etc…. Thanks Geo