Based on other reports of this kind:

Overlays or Video recording (eg GeForce Experience, OBS or Steam Bigpicture) running simultaneously. GeForce Experience is installed by default. Steam also runs their overlay by default on all games purchased through Steam. Likewise Discord is known to do this.

I know that these things, stand-alone tend to work fine, it's the combination of certain overlays that tends to do it.

My i7-4770 runs a GTX 1080, and has 32GB of ram, and Ive never had this problem with FFXIV on Windows 10. I have the same GPU driver and Windows version you do. For all intents the only difference is the CPU. But I don't run the Discord App, and don't run FFXIV through Steam. I use GeForce Experience only.

Based on the "green symbols" description, I'm more willing to say it's GeForce Experience that is the direct cause, but it might actually be something else. The way overlays work is that they hook themselves to the end of the displaylist render call, and typically only one overlay will ever work correctly without being aware of the other. Some overlays check for other overlays to make sure they are loaded after graphical overlays but before video capture ones.