Hi Kelsey,
This is the behavior of subtasks in Asana - if you add them to a project, they show as a task in the project in addition to still showing as the subtask. It’s widely viewed as an unfortunate behavior but it’s what we have for now. The standard workaround is to make a section called something like “Subtasks - Ignore”, move it to be the bottom section, and keep it collapsed. “Out of sight, out of mind.”
You might want to also vote here: