CAS device is running version prior to 22.214.171.124.
When do a "Test Syslog" under Settings > Alert Locations, packet capture shows no syslog traffic been sent out.
However when the CAS device was restarted, doing the same test, packet capture shows syslog traffic been sent out but subsequent test fails.
The server setting is using a hostname and also an IP.
Release : 126.96.36.199
Component : Syslog
This is a bug affecting version prior to 188.8.131.52.
Upgraded to 184.108.40.206 and it resolved the issue.