Why Wrong/Default Variant gets added to the cart everytime?

Hi to all Shopify experts, Please help with this problem I am unable to fix it.
I’ve checked other discussion related to the same issue but it doesn’t work for me. My problem is when I select a Large size on the product then click add to cart. When I view a cart the product size shown was a small size which is the wrong size.

Happening with every product.
Though adding from the panel at the bottom (activates when you scroll a little) it works fine then.

Console Log :

Link to a product : https://joyofshru.com/collections/best-selling/products/divena-floral-printed-cotton-empire-ethnic-dress

I’ve used a paid theme from envato, here is the documentation : https://themessupport.com/wedesigntech/shopify/trendz/

If this is happening with every product then definitely there is a bug in the code. It does happen and I have experiences clients facing some issues when using a paid theme.

This will need debugging and from my experience I can say that this is not a huge issue the main issue is to debug the code base where the issue is as different themes have different code structure and style.

Definitely will need collaborator access to your store since you are using a paid theme. Please reach out via mail for a convenient conversation and collaboration

Best

Shadab