Drops "TCP Out of Sequence" even after creating excepcions

[arcotangente]

Hi guys,

We are troubleshooting a random issue with a connection between 2 internal hosts and some external servers on a cloud provider. We don't know if it is related to the issue or not, but we observe in the firewalls logs some "TCP out of state" packet drop.

Most of the drops have "ACK" as TCP flag, and some "PUSH-ACK", as shown on the screenshots attached. 

So we went to Inspection Settings and for our gateway we added the source IPs (only the source, Any destination) and the destination port (443) as exception for the protection "TCP out of Sequence". However nothing has changed, and the gateways keep dropping the packets for time to time.

The gateway cluster is a 4000 series running R80.10

Any help on this?

Thanks