I have been getting started with materials and wanted to create a lo-fi scene with a dark marble material. I followed a tutorial to create the marble material, which works great. I then modified it using another tutorial to make it look more pixelated and retro. Here's the node graph:
And the preview looks like exactly what I want:
However, when I apply it to faces in my scene only some of them render the material correctly. Others distort the material into strange angles:
The faces marked with a green dot are rendered correctly, those marked with a red dot are inexplicably distorted. It works just fine if I use the more realistic material by disconnecting the snap node from the bottom voronoi node. This happens in both Eevee and Cycles, in previews and final renders. What gives?