I have installed Magento2.3.3 on my system and created one configurable product which has two swatch attribute colour and speed. Colour is image swatch and speed is dropdown. So upon loading product out of stock swatches are showing clickable means there are no red line on it.
Here I'm attaching a screenshot where colour Champagne Gold and speed 820 RPM product is out of stock but still, it is clickable.
I'm not getting any errors in the console. Any help will be appreciated.