Add to Cart button greys out for size/color variants

[Abby_MayArt]

I recently noticed that my size variations for prints on my shop, and for newly added printify items variations aren't working. Every time I select a different size/color, the add to cart button gets grayed out and I'm unable to add the item to my cart.

I double checked the stock for the items (all untracked as they're POD items), I made sure to select all the size/color variations from printify so I don't think it's an issue there. I suspect it might be something with my theme.

[Abby_MayArt]

Could I get some help with this?