Date & Time: 08/10/2020 11:03
Frequency: Anytime I log in (game is now unplayable)
World Name: Lich
Character Name: Selphie Kinneas
Party or Solo: Both
In-Game Time: After login screen (login screen is reporting 120 FPS like normal)
Area and Coordinates: Happens anywhere
Steps:
1. Login
2. When loading into the game you can see the FPS drop with an FPS counter (built into the monitor, not software)
3. FPS stays at around 22-23hz

GPU performance change before and after you started having the issue: Previous NVIDIA drivers 432.00 via Windows device driver install (letting Windows install its own rather than going to Nvidia directly)

GPU: Nvidia Geforce RTX 2080 Ti
Driver Version: 456.71 or 456.55
CPU: i7-6700K CPU @ 4.00 GHz
RAM: 16G
Hard Drive: Samsung SSD (NVME) 970 EVO Plus 2TB
OS: Windows 10 Pro
OS Version: 1909
Graphics Settings: Maximum 3440 x 1440
FPS Limit: (System Configuration > Display Settings > FPS Limit) No limit

So here's my take on this. I've had this issue in the past as well and to me it seems more like an nvidia issue. I can get the game to play flawlessly if I don't install any nvidia extras just using Windows 10 to download the driver automatically. The latest drivers always seem to mess everything up. Only issue is, without newer drivers you can't play newer games hence this post. I've just reinstalled 432.00 drivers and the game runs perfectly. Haven't been able to figure this out, it's not gsync either as I've tried on and off. With the faulty drivers, FF14 runs perfectly in windowed mode as well, but not full or borderless. At a loss with this one.