Dropdowns with blank"select one" option, not required, AND use inventory variants?

[teedle]

My problem is really specific... I have the default label in the dropdown hidden and replaced with just a blank select one like here

https://www.miva.com/blog/quick-tip-how-to-add-select-one-to-your-drop-down-menus-with-attribute-mach/

(We're just using labels above each attribute instead of inside the dropdown, that's why I hid the normal top option)
On normal products it works perfectly, you can leave it on "select one" and add to cart with that option left blank. But as soon as I generate inventory variants for a product, it will gray out the add to cart button until that attribute is selected (even when it isn't required). Anyone know what could be happening?
Thank you!

[Matt Zimmermann]

Have you set the attributes option to say that the select contains a Select One?

[teedle]

Have you set the attributes option to say that the select contains a Select One?

Yeah it's on "Preload - Drop-Down Lists Contain Select One" and it definitely works on non-inventory variant products. Maybe it grays out add to cart because there technically isn't a variant including a blank selection?
There might not be a way to have it work like how I want it.

[Matt Zimmermann]

Yes, when you do not have a valid set of attributes selected, the add to cart button will be grayed out.