Your product is not showing on Mash&Grape or is showing as Out of Stock on Mash&Grape because you are currently enrolled in the LITE plan on Flaviar Checkout, which allows you to have a listing on Mash&Grape but we only show the products available and in stock if a retailer in our retailer network already carries the product.
If you are a Flaviar Checkout "paid" user we have agreements with our retailer network that they must bring your product in if available and keep stock levels allowing to list your products on Mash&Grape and show as in stock.