Issues downloading Game Files (Australia)

[Arcturus_]

The Computer is connected to the router via ethernet switch, just to extend range. Have tried installing connected directly to the router, connected to another modem/router at another house using a different ISP, and tethered to my phone. Friends and family members have also had this issue on different connections and some on brand new PCs, same solution has been to install a one time use VPN and install during their trial window.

Everything I've tried so far:
-Created a trial account and tried installing the non steam version of the game, same error.
-Installed with compatibilty layer selected in launcher properties and administrator elevated permissions.
-Backed up user files and wiped all FFXIV files from my computer, problem persists on reinstall.
-Tried multiple different DNS, flushing DNS every change.
-Isolated computer on the network with no other devices connected.
-Reset all modems used to factory settings.

If it is a routing issue, I don't think it's solvable with the ISP, considering I've tried three different ones with the same results. Still thinking of stuff I've missed, I could try port forwarding but I don't know what ports I'd have to open.