Hi,

You can export the product variants, add variant values, and then import them back. For detailed information, please refer to the blog below:

https://www.cybrosys.com/blog/how-to-import-product-attributes-and-product-variants-in-odoo-17#:~:text=For%20importing%20product%20attributes%2C%20we,are%20already%20created%20in%20Odoo.

Hope it helps

Hello,

​Ensure that the variants of the product is correctly configured in the Attributes & Variants  Tab in the Product page. 

And restart the server to get the updated data in the odoo. Most of the time, these type of issues are sloved by restarting the server.

And then check the Product Variants page. [Inventory/Products/Product Variants]

Check and Clarify your Doubts.