The health check on your ProxySG appliance produces a health warning for the DRTR/WebPulse service. When reviewing the details only one IP address appears to be unhealthy: 220.127.116.11.
This is typically an issue caused by running an older version of SGOS. The DRTR servers all use TLS1.1 with the exception of 18.104.22.168 which uses TLS1.2. Starting in SGOS 22.214.171.124 a new TLS1.2 extension has been added called ' signature_algorithms' in order to conform with the TLS1.2 RFC. This means that prior to 126.96.36.199 any DRTR connection will fail when a connection attempt is made to 188.8.131.52 as the server is expecting the missing extension.
This issue is documented in bug 220955 which is a duplicate of 220955 and has been fixed in SGOS 184.108.40.206 or greater.