System Information

• Minecraft Version: 1.17
• Canvas Version: canvas-mc117-1.17-1.0.1762
• Operating System: Windows 10
• Graphics Card: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2 GL version 3.2.0 NVIDIA 471.11, NVIDIA Corporation

Other mods and versions installed
Only canvas

How you triggered the behavior

• create a world using custom world height (below y-level -64) Datapack: [extendedheight.zip] (https://github.com/grondag/canvas/files/6794983/extendedheight.zip)
• Go to y -64

What you expected would happen

• Chunks would load normally

What actually happened

• Chunk loading completely breaks

Logs and screenshots
latest.log