user-4f496

Was able to reproduce in 1.16.5.

I have a feeling that some mojang devs are aware of this as basalt's blockstate uses _{"x": 90} and _{"y": 90} as a workaround to rotate _{"z": 90}. Don't even know if z axis rotation exists in blockstates.

{
  "variants": {
    "axis=x": {
      "model": "minecraft:block/basalt",
      "x": 90,
      "y": 90
    },
    "axis=y": {
      "model": "minecraft:block/basalt"
    },
    "axis=z": {
      "model": "minecraft:block/basalt",
      "x": 90
    }
  }
}

Same, I'm confused as to how it only happened once.

The thing is, I generated the world again and it was normal. Is there some variation when it comes to generation of structures, even when in the same seed?

Large Biomes, Seed: -863292574740581612

Coords: 19 90 3270

I can share the save itself, don't know how to share a folder here tho. It's over the limit of 10MB.

Seems to be in the newest 1.14 snapshots as well. 18w44a has it.

Thanks for the quick response, here:

 Here is one with just the top part of the rails: