WooCommerce Min/Max Quantities not working

It seems that the official WooCommerce Min/Max Quantities plugin:
https://docs.woocommerce.com/document/minmax-quantities/ has an issue that prevents it working correctly.

For example;
– I have a T Shirt product set up to be purchased in a minimum quantity of 4, with ‘Allow combination of variations to satisfy the min/max rules above.’ checked. https://snag.gy/kPZvFX.jpg

– I have the colour variables (red, green, blue etc.) set to groups of 2. https://snag.gy/yT57QN.jpg

So, with the above I should have to add x2 colour variables, equalling 4 T Shirts, to hit my minimum purchase quantity. However, it lets you add just one variable (2 T Shirts) to your cart and checkout. No notices, no errors, nothing.

Does anyone else get this issue?

I’ve tried a clean WP install using Twenty Ninteen, and just running Woocommerce and the WooCommerce Min/Max Quantities plugin.

I also raised this with the Woo team over a month ago with no progress seemingly being made.