"coś" requires a form that ends with -ego. Whether it's Accusative or Genitive, I'm still not sure. Probably Genitive, as 'coś' itself is neuter and for neuter, only Genitive ends with -ego.

it's always neuter. but for some reason nominative and accusative of something+ adjective, are

coś+ adjective in genitive

While it's not impossible, that would suggest that I want to eat something good... all the time? And especially with 'something', this sentence really sounds like what you wish to eat right now.

That would sound rather strange.

True. The algorithm isn't good with understanding the types of mistakes.