If I list the item as “out of stock” the label changes to red and says "OUT OF STOCK" on the product. If I set it as “in stock” the product says "Availability: not in Stock"

I can even set a specific quantity and manage stockkeeping and it still says "Availability: not in Stock"

I don’t know what the difference between “not in stock” and “out of stock” is but the latter is bold, red and clearly a problem. The “not in stock” label shows up no matter what and you can still buy a product.

Where is this property kept? What is it tracking and how do I get this to go away?