This issue has been fixed in SGOS 220.127.116.11, SGOS 18.104.22.168 and later.
This issue is not relevant in SGOS 6.5, since SSL code in 6.5 already contains the fix.
In explicit deployment, this issue can be easily avoided by disabling protocol detection:
url.domain=<URL> detect_protocol(none) ALLOW
In transparent proxy deployment, disabling protocol detection doesn't resolve the issue. Static bypass or TCP Tunnel proxy service are possible workarounds.