Cart page

Here’s a fix for the issue. The product data should be added to the woocommerce_quantity_input_min filter arguments, and retrieved that way rather than using get_the_ID() which will get the ID of the cart page instead of the product.

function wcmmq_s_set_min_for_single($min_quantity, $product){
    //$product_id = get_the_ID();
    //$product = wc_get_product( $product_id );
    $min_quantity = get_post_meta($product_id, '_wcmmq_s_min_quantity', true);
    $min_quantity = !empty( $min_quantity ) ? $min_quantity : WC_MMQ_S::getOption( '_wcmmq_s_min_quantity' ); //Regenerate from Default
    if( !$product->is_sold_individually() && ( !empty( $min_quantity ) || !$min_quantity ) && is_numeric($min_quantity) ){
       return $min_quantity;
    }
    return 1;
}
add_filter('woocommerce_quantity_input_min','wcmmq_s_set_min_for_single', 10, 2);