Hi there,
By default, it shouldn’t be possible to add a variable product to the cart when no variation has been selected.
Below is what it looks like on a sandbox site where WooCommerce is the only active plugin and the theme is Storefront in Firefox, Chrome and Safari respectively:



As you too switched to Storefront when your issue occurred, it appears that one of your other plugins, or perhaps custom code you’ve added, is interfering with the default functionally. I’d suggest a conflict test to get to the bottom of it. Here’s a guide to help you along:
https://docs.woocommerce.com/document/how-to-test-for-conflicts/
Hi!
Thanks for your feedback!
I disabled all the plugin except for WooCommerce and used Storefront.
As I said, it only happens when loading, so you should try multiple time because it’s really fast.
I have made another video here, please look at the button when I refreshed the page, it was activated while loading, try click during this time and try multiple time, you will see the issue.
https://www.loom.com/share/3a703155b7d948e487c2665fdb3094f8
i add my voice there is really a bug
some of my clients gets orders with these product without choosing variations
we wonder how they are able to do this and this video shows this option so there might some old or slow computers or browser which enable this bug or whatever
bottom line we get like these order couple in a week and there should be a solution!!
Hi there,
It seems like a similar issue was described in this Github issue, for which a fix was released in WooCommerce 4.7.1.
Please follow best practices to update your WooCommerce, and let us know if this update fixes the issue for you too.
It’s been a while since the last reply to this thread, so I’m going to go ahead and close it. If you require help with anything else, please feel free to start a new one.