There are two reasons for this behavior.
To resolve this issue, configure ProxySG to bypass SSL interception for the hosts involved.
Example hosts:
We then will need to bypass the Line messaging IP range “203.104.160.0 - 203.104.175.255” from the ProxySG, steps as below:
To bypass:
Proxy settings: Proxy: SSL
Listeners: Source: All ; Destination IP: 203.104.160.0/20 ; Port range: 443 ; Action: Bypass
To TCP Tunnel:
Proxy settings: Proxy: TCP Tunnel
Listeners: Source: All ; Destination IP: 203.104.160.0/20 ; 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.