Some time in the last 24 hours, a bug was added to the Babylon repo: https://preview.babylonjs.com/babylon.js
If an object is loaded in, and then instanced at any point after, and then cloned at any point after, it can’t be instanced again without breaking all of the meshes except for the cloned one.
Below is a playground showing the problem in the simplest way I could find. The intended behavior would be for 4 tables to appear. Instead, 3 appear and then the 4th one breaks all except the 3rd (cloned) one. Once the tables disappear, you can move the camera around and see black lines and triangles all over the screen.
Here’s the playground showing the problem exactly: