Why does my Shopify product show sold out when inventory is in stock?

That usually means the stock is in the wrong place from the online store’s point of view. Shopify can show inventory on hand at one location while the location that actually fulfills online orders has zero available for that variant, which still makes it look sold out to shoppers. Open the exact variant, not just the product total, and check Available inventory at every active location. Make sure the location holding the stock is set up to fulfill online orders and that the stock isn’t marked unavailable or committed. If you use a fulfillment or dropshipping app, check its location and shipping setup too.