This solution applies to the Barracuda Web Security Flex Agent, when in use behind an upstream Web Filter,
That is set to ACTIVE mode to filter traffic and disable itself properly. 188.8.131.52 and up
The WSA should sync behind the Web filter even though it should be disable to not use the WSA anymore, when checking for connectivity the first time.
Issues persisting with inline sync. Most issues are related to the nature of the network setup.
When WSA detects it is inline from the VIA header being passed to our server checking and back to the WSA(found on the Advanced tab> proxy page) , it will run the sync and then disable itself.
The sync will occur on the IP address set in the remote filtering settings. If it is an FQDN host, we need to see, what it was resolved to when syncing.
If inline sync fails with the latest WSA version or Beta version, please get a packet capture and check if the sync request sent a SYN and got a SYN,ACK back from webfilter.
Otherwise, it most likely will be the network setup. Escalate the case as necessary with all the data grabbed from that machine incl. pcap from that WSA machine.