Thank you for the update everyone.

There are a few suggestions I missed in the previous post.

Makes sure you have a wired connection (as opposed to wireless) if you do not already.

Check the following Port Ranges on your router/modem to ensure that the following Port Ranges have been opened/forwarded/triggered:
▼TCP
54992 through 54994,
55006 through 55007,
55021 through 55040

Your ISP may forward these ports for you.*

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!