I don't think that is it. I am having a similar but different situation where my in-game textures are disappearing. I have Discord but I have the overlay turned off. This started with patch 3.5, but every so often, I would loose in-game textures. At one point it kicked me out of the game while the issue was in place. I am using the latest Radeon Drivers for my graphics card so it's not that. And this is not happening to any other game. I even had every other program shut down (including Discord) and it still happened. Here is two examples of it happening last night

https://i.imgur.com/7XGTVli.jpg
https://i.imgur.com/X5jBpg2.jpg

I tried with both Direct X 9 as well as Direct X 11.

This tends to happen more often when there is a sudden graphic lighting happens