Hi,
The issues might come from the fact that ODSEE has implemented RFC 2307bis - which aimed to improve on the old RFC 2307. As far as I know this never got a real standard - even though some companies adopted it.
RFC 2307bis defines some things slightly different. from RFC2307. One of those cases is the gecos field which is a Directory String (SYNTAX 1.3.6.1.4.1.1466.115.121.1.15) and can take UTF-8 character.
Have a look here https://docs.ldap.com/specs/draft-howard-rfc2307bis-02.txt
Regards
Felix