I listed some troubleshooting steps inthis Forum post for a similar situation — feel free to go through it to see if that'll resolve your issue.
You can also double check your products on cart and ensure that they've been marked as aphysical productwithin the product page on your store's Shopify admin. Check out theShipping section of this help guidefor more information on this.
If you haveShopify Marketson your store, you can also navigate toSettings > Marketsto check if the all shipping regions on your store are active. If a region you wish to sell to isn't currently active on your store, you can clickManage > Market status > Activefor the market you'd like to activate. More information on Markets can be found onthis help guide.
If you still can't pinpoint where the issue is stemming from, our live support team can help take a closer look at your account from our end. You can get in contact with our support teamvia our Help Center here. Once logged in, select a topic that best fits your query or situation. From there, you'll be taken to a page with a list of relevant support articles, and you can scroll to the bottom of that page to select your preferred contact method with our team.
Apart from this issue, how are you getting on with your store? If there's anything else that you're currently working on that you need further help with, feel free to reply here to let me know.
Kimi | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog