i am trying to connect to remote server

SQL> connect sys/change_on_install@wizerp
Connected.

SQL> connect sys/change_on_install@wizerp as sysdba
ERROR:
ORA-01017: invalid username/password; logon denied

Warning: You are no longer connected to ORACLE.

Can u guide me what could be the reason for not connecting as sysdba but it is connecting successfuly without sysdba