On PacketShaper S-Series, the SSH daemon is part of the base operating system. Therefore, SSH syslog messages are designed to be sent by the base OS itself.
Since SSH daemon is not part of PacketShaper Syslog feature, syslog messages can be sent even when the feature is disabled (setup syslog state off) or when PacketShaper syslog is configured to send messages at different levels.
The only way to stop the syslog messages from SSH is not to configure the syslog server IP address.
You can filter the messages on the syslog server side if needed.