The Symantec Web Gateway SSL Decryption proxy, running on port 8443 by default, always presents the intercepted cert as a SHA1 cert with no currently supported ciphers.
Since the Symantec Web Gateway went EOL, SHA1 certificates are no longer trusted by current releases of majors web browsers (Firefox, Chrome, Safari). There is no solution at this time since the Web Gateway product is End of Life and will no longer be supported after December, 7th, 2019.