Hi there,
To clarify, when using Shipping Classes + the Flat Rate shipping method, you would be setting the price for that specific class in the shipping method, however would not cause it to show a “Free shipping” method/option separate from the Flat Rate method. We have a guide for setting up free shipping like this available here:
https://docs.woocommerce.com/document/flat-rate-shipping/#section-4
As described in the documentation above, you would be setting the main “Cost” for the Flat Rate method to 0
or blank. Then you would set the “No shipping class” and other shipping classes as appropriate, and set the “Free shipping” class to 0
also.
If you are still having trouble, please send a screenshot of your settings for the Flat Rate method, and your list of Shipping Zones under WooCommerce > Settings > Shipping. I recommend https://snipboard.io for easily sharing screenshots – please follow the instructions on the page, then paste the URL in your reply here.
Also, please send the URL to a test product on your site, and the shipping address you are testing with.
Thank you!