- Switch between fullscreen and borderless windowed modes.
Tried already, no difference.

- Update and reinstall the drivers for your graphics card and sound drivers (if applicable). Should the issue persist, please try a clean reinstall instead.
Tried this four times over prior, no difference.

- Please try adjusting/lowering the resolution.
Tried already, no difference.

- Please try running the game as an administrator.
Tried already, no difference.

- Perform a clean boot by opening the task manager and select the 'Start up' Tab. Disable everything.
Tried already, no difference.

- Please be sure that Final Fantasy XIV is installed to the C: Drive.
It is.

- Please be sure to disable or remove any overlays (Discord, Steam, NVIDIA etc.) as they may interfere with startup.
Tried already, no difference.

- Make sure that the Windows OS is fully updated.
Updated, no difference.

- Reinstall game.
Tried already, no difference.

OneDrive I've had disabled for a very long time.
FFXIV has only ever used my 3080 Ti, never had it switch to the other at all. Issue still persists even if running the 3080 as my dedicated GPU.