Replace member=%{Ldap-UserDn} with member=%{control:Ldap-UserDn} in the groupmembership_filter as per the default configuration.
# groupmembership_filter: The filter to search for group membership of a
# particular user after we have found the DN for the group.
#
-# default: (|(&(objectClass=GroupOfNames)(member=%{Ldap-UserDn}))(&(objectClass=GroupOfUniqueNames)(uniquemember=%{Ldap-UserDn})))
+# default: (|(&(objectClass=GroupOfNames)(member=%{control:Ldap-UserDn}))(&(objectClass=GroupOfUniqueNames)(uniquemember=%{control:Ldap-UserDn})))
#
-# groupmembership_filter = "(|(&(objectClass=GroupOfNames)(member=%{Ldap-UserDn}))(&(objectClass=GroupOfUniqueNames)(uniquemember=%{Ldap-UserDn})))"
+# groupmembership_filter = "(|(&(objectClass=GroupOfNames)(member=%{control:Ldap-UserDn}))(&(objectClass=GroupOfUniqueNames)(uniquemember=%{control:Ldap-UserDn})))"
# groupmembership_attribute: The attribute in the user entry that states