So.

I haven't been able to get a good picture of this because it's so hard to spot. At first didn't even think it was related to the game itself as I was working on my own project at the time, but since I've noticed it crop up in actual gameplay on a 1.13 server.

Here's what happens:

Every so often, sometimes minutes (it seems to become more common in more complex surroundings) one of the items in my hotbar would randomly flicker, and one corner will jump to infinity causing a brief discoloured flash across the screen.

Then, a frame later, it snaps back to normal. And... that's it.

Gl meshes break for some reason and I can't for the life of me know why. Have never seen it happen before 1.12.2 and it's oddly annoying to see a random texture glitch whilst standing around fishing.

If someone can find some pictures of this happening, I'd greatly appreciate that. Searching for "model vertices break" turned up an underwhelming amount of results, so I presume this hasn't been reported.