@KK Sir,
I injected my code (alongwith JS) into the simple-couchified.zip's index.php code.
The cart still functions and the cart-modal.php gets executed. There is no JS issue there.
After additions the index.php of cart is similar to my product.php, especially in terms of the JS.
I injected my code (alongwith JS) into the simple-couchified.zip's index.php code.

The cart still functions and the cart-modal.php gets executed. There is no JS issue there.
After additions the index.php of cart is similar to my product.php, especially in terms of the JS.