There are two reasons for this behavior.
To resolve this issue, configure ProxySG to bypass SSL interception for the hosts involved.
We then will need to bypass the Line messaging IP range “184.108.40.206 - 220.127.116.11” from the ProxySG, steps as below:
Proxy settings: Proxy: SSL
Listeners: Source: All ; Destination IP: 18.104.22.168/20 ; Port range: 443 ; Action: Bypass
To TCP Tunnel:
Proxy settings: Proxy: TCP Tunnel
Listeners: Source: All ; Destination IP: 22.214.171.124/20 ; Port range: 443 ; Action: Intercept
Note: The addresses provided are valid as of March 2, 2016 and may change. If they do, use a packet capture to identify the new hosts used to handle Line messaging communication or contact Symantec support.