SE replied to my email
Thank you for contacting the Square Enix Support Centre.
We are sorry to hear that you are experiencing connection issues with Final Fantasy XIV: A Realm Reborn on PS4.
We can advise the following, in order to try and resolve the issue:
1) Firstly, power cycle: Turn off your modem and PS4 for a good 5 minutes. Turn on your modem/router first, and wait until it's booted up completely. Then turn on your PS3.
2) Go through Settings -> System Settings* -> Restore Default Settings -> This will clear any and all settings on your PS4, leaving any data intact.
3) After you've correctly set up your PS / Network Connection, try again.
4) Make sure you have sufficient WiFi connection (if applicable) This should be at least 75% signal strength, and consistent.
5) We recommend using a landline based Internet service (ADSL or Cable etc) If you are using 3G / 4G, you may experience issues due to the nature of those types of services.
6) If you still experience issues, we advise contacting your ISP to see if there is anything that can be done in regards to connection issues.
We hope this helps resolve your issue, and we apologize for any inconvenience caused.
Kind regards,
The Square Enix Support Centre team
Who gonna try these

?