Creating Blocks with Area Hatch/Fill in them

Hi All,

I am trying to make a Block with this: -

https://preview.redd.it/jys1v15invxd1.png?width=704&format=png&auto=webp&s=ede228f0309f876a373c833b6df6a2b87f0ce399

Simple right? Well for some reason the Area Fill/Hatch that I used to get solid triangles does not want to come through to the Block. Whenever I go to make the Block I end up with empty triangles. Anyone know of a fix?