Elias here with Shopify Support. Thank you for reaching out!
I understand that several items in your store are showing up as unavailable or sold out, although they are available or in-stock. Just to clarify, is this happening with all your products, certain products, or certain variants?
There are a couple of areas that we'll need to check, such as each product's/variant's inventory levels or inventories assigned for your locations. If you've enabled inventory tracking, you can view your inventory levels and check if your products and variant are reflecting the correct quantities.
If the inventory levels are correct and the issue persists, then it's possible that you may have multiple locations set up. If so, you'll want to review the priority of locations for fulfilling online orders and ensure that your locations are set up to fulfill online orders. If applicable, you can also prevent certain locations from fulfilling online orders. After that, you'll need to make sure the locations fulfilling online orders have the right inventory levels, by assigning inventory to each of your locations.
I hope this helps! If the issue persists or if you have any other questions, please don't hesitate to let me know and I'd be happy to take a closer look!
Thank you for following up!
So that I can take a closer look, can you share an example of the issue? If possible, preferably a screenshot of a product with the issue from your storefront and from the admin. Also, can I get your store URL (.myshopify.com)?