button selection when variation does not exist

Hi,
I have seen other posts similar to my issue, but they are marked private.

I have a product that has lots of colour variations. But some combinations do not exist, for obvious reasons.

For example, Black box with black print is not a valid variation, it doesn’t exist.

But, the black box for box colour, and the black box for text colour are selectable together.

How can I stop them?

The Hide ‘out of stock’ variation item option is set to true
The Out of stock option in Swatch Profile is set to hide.

I currently use Variation Swatches for WooCommerce, which does this perfectly.

What do I need to do?