oracleDB plugin don't work with user "sys as sysdba" #1100

moin.
sometimes it´s needed to connect as sysdba which means you to connect with a user string like this:
'sys as sysdba'
i can enter sys as sysdba into user field with quotes or without quotes both dont work.
oracle states: ERROR-01017 invalid username/password; logon denied
connect as user e.g. "oracle" works as expected.
sysdba credentials works in sqlplus.

any hints ?
cheers