It worked fine every other time. Then I joined in my creative world today and the chunk that my displays were in could not render the visuals, but the blocks were still there. This happened in two dimensions. How I figured it out is in steps below.

1. Found the display in one dimension
2. Broke it
3. Left that dimension
4. Re-enter that dimension
5. That chunk started rendering again
6. Repeat everything for the second dimension