ChunksWithin does not return all chunks within the provided range.

[james0x0A]

It seems like the function is only returning chunks on line, ie X=Y. The method of creating the enumeration uses a zip function that is essentially for x and y yield (x[n], y[n]) and thus the result is often something like (0,0) (1,1) (2,2) (3,3)

Edit: here is my rewrite of the method https://gist.github.com/james0x0A/211ad392c728ae3d632145266cd63f7c