Structures are getting cut off at chunk lines, and the random code doesn't work properly

For some reason, at the chunk lines part of my structure get cut off... I am trying to generate an RNG castle, that has a giant outline and a randomized inside, but at every chunkline a large section is cut off... Solution?

Also, on a related note, the random code line:
(If: [Random {1,0}] = {1}
[place {X} {Y} {Z} Structure: {cmiddle1}]

else:

[place {X} {Y} {Z} Structure: {cmiddle2}]

that code line will always generate the first one no matter what for me....