Wrong 'Authenticated Identity'(?) Using Proxy in SQL Developer w. Kerberos authenticated CMU

I have a question about how proxy connection works and should be specified when doing SQL Developer connection.

Scenario:

I have a connected Kerberos user: myName@MYORG.COM

In Kerberos (i.e. in MS Active Directory) the user is member of a group MYGROUP@MYORG.COM

On the database I have a user MYGROUP which is create something like "create user MYGROUP identified globally as 'cn=MYGROUP, ou...,dc=MYORG,dc=COM';"

And onther user APPSCHEMA which have been given proxy privs like: "alter user APPSCHEMA grant connect through MYGROUP"

From a windows PC AD(Kerberos) authenticated as myName@MYORG.COM i can start sqlplus and do a connection with "sqlplus [APPSCHEMA]@tnsalias". That will connect and "select sys_context('userenv', 'authenticated_identity') from dual;" will return "myName@MYORG.COM"