I have seen improvement after doing this - Under the "General" tab, please delete ALL browser history.
- Under the "Security" tab, please move the slider to the lowest possible settings or no higher than "Medium"
- Under the "Privacy" tab, click “Advanced” and select ‘Accept’ under both First Party and Third Party Cookies.
- Under the "Advanced" tab, please make sure that "Allow software to run or install even if signature is invalid" is CHECKED.
- Make sure that all SSL and TLS (EXCEPT SSL 3.0) are CHECKED. [SSL 3.0 should be UNCHECKED]
- Hit "Apply" to save the settings, and then "OK, to close the Internet Options menu.
- Right-Click on the FFXIV launcher icon and select "Properties"
- Hit "Apply", then "OK" to save the changes.
- Please RESTART your PC now. Once your PC has been restarted, Right-Click the FFXIV launcher icon once more and select "Run as Administrator"
*Make sure your fire wall or antivirus program is not interfering with the game

and

- Flush DNS: Within the "Command Prompt" of the device, please type the command "ipconfig /flushdns".
- Reset TCP/IP: Also within the Command Prompt, type the command "netsh int ip reset" and then restart the computer.
- Delete the Patch Folder: Navigate to the folder using this path This PC > Docs > My Games> FFXIV ARR > Downloads > FFXIV patch
Then either rename or remove the folder, the next time FINAL FANTASY XIV is launched, the client will repair the folder.
- Change local DNS: Please try changing the local DNS server to 8.8.8.8 and 8.8.4.4
- Delete local files with corrupted character data, please note this will not delete the associated characters.

but i will keep an eye on it in case it happens again.

Thank you!