Hi there! I've been having a strange issue with XIV recently, started happening soon after BLU was made available to play.
The main one is the game crashing with the generic 11000002 error when only playing in dx11

The second issue happens with dx11 and 9c. There's regular freezing, forced minimizing and flashing blue/red/white/yellow circles across the top 1/3 of the screen in full screen, windowed or borderless window. In the task manager the GPU utilization jumps to 100 in the freezing and black screen.
I've uploaded a video of this happening: https://youtu.be/8MIQD9MqYfg

I've tried updating drivers, DirectX, clean installs of both and even a clean install of windows on a wiped SSD from another system. I've also fiddled with a lot of settings in game and watched temperatures and clock speed while in windowed. the circles seem to emerge around 53 degrees Celsius regardless of settings. Thinking it may be my system I tested other games that may push it a little harder (Battlefield V, FFXV among some others) and found nothing resembling this.

System specs:
CPU - i7 9700k
GPU - 2070
Memory - 16gb 3200MHz XMP 1
SSD - Samsung 840 evo
HDD - WD black
Monitor - Acer X34p using displayport

I've run out of ideas, though I'd ask here before contacting Square directly. If there's more info needed I'll do what I can