Packet loss gets crazy whenever FFXIV is booted

For some reason, whenever I boot XIV, packet-loss with everything else just skyrockets. It's just XIV, not any other online games that I've checked, and I'm on a built-in WiFi card. It's just gotten worse and worse ever since Endwalker came out, and I'm at a loss as to what the issue is.

I had initially thought that I was too far away from the router to get a consistent 5GHz connection, so I blacklisted my PC on my router on the 5GHz band. Now, I've moved my PC closer to the router and I should be able to get that consistent 5GHz connection, but now I'm realizing that it's just XIV causing these issues, and other games that would probably cause the same issue haven't at all. I'm just at a loss to what the problem might be (other than to just wire up, which I hope to at some point soon).

Edit:

To clarify, I'm playing on Windows (No Steam), and the issues begin as soon as I boot the game up and get to the title screen.