Disabled LDAP accounts disappear


we have installed NC 12.0.0 on Ubuntu 16.04 with acutual php, apache, etc. We import user accounts by LDAP. If we disable LDAP accounts via web administration or command line, these disabled LDAP accounts completely disappear from the web gui, they also do no appear in the explicit group “Disabled”. If we disable local accounts, they immediatly appear in the group Disabled.

If we (re-)enable the LDAP accounts, they come back.

Are these disappeared LDAP accounts a bug or a feature? We would expect that they appear in the group Disabled too.