This started happened sometime after the 5.08 patch. The only other updates Ive might of had is a windows update on 9/10 (Windows 10). I don't have any other updates to my PC or new programs beyond that.

I only experience the 90k error after leaving a duty, haven't had the issue starting duties, or logging in/reconnecting.

I'm not sure what else to try at this point, I don't know the port FFXIV uses to ensure its open fully, but FFXIV is allowed through my firewall.