Server Disconnecting Clients - Wireshark Proof - Server sending FIN TCP flag- BUG

[Moronica]

That really sounds like a problem on Square Enix’s end, or at least with the data center they’re using.

Do you still have a Wireshark capture from a disconnect? I’d really be interested in the TTL values. If the TTL of the FIN packet is identical to the packets received before, the FIN most likely came from the server itself. But if e.g. the TTL of the FIN packet is greater by 1, it may have come from the node directly before the server (assuming both use the same TTL for packets they create).

The fact that the connection is closed by a FIN instead of aborted by a RST also points more to a problem in the data center IMO than to a problem with your router or anything else on your end.

From the data center’s point of view, both your and your wife's PCs are indistinguishable, because they both use the same public IPv4 address (which you get from your ISP). Maybe the data center’s DDoS attack detection is “misinterpreting” multiple TCP connections to your IP address as some sort of “attack” and kills one of them? But you get the disconnects also if you’re trying to play without your wife, right? (I’d also expect to see a RST in such a case instead of a FIN, or the data center’s firewall simply swallowing packets silently without any reply at all.)