\Subscribed attribute is not returned for subscribed folders when requested. E.g.

C: A0006 LIST (SPECIAL-USE) "" "*" RETURN (SUBSCRIBED)
S: * LIST (\HasNoChildren \Drafts) "/" "Drafts"
S: * LIST (\HasNoChildren \Sent) "/" "Sent"

Tested with Cyrus IMAP 2.5.9.11-Kolab-2.5.9-12.2.el7.kolab_wf.
I originally created a ticket at https://github.com/cyrusimap/cyrus-imapd/issues/11, but it looks that it might be Kolab-specific issue. Is it possible?