Woocommerce cart quantity change stop changing the final price - php

Question

By default when woocommerce cart quantity is changed it updates the item price by multiplying it by the quantity. I would like to change the default behaviour and ensure that when in the cart when the quantity is changed it doesnt change the default price passed when add to cart is clicked
I have added this action hook but i cannot figure out how to stop price change when quantity is changed in a cart.
add_action( 'woocommerce_after_cart_item_quantity_update', 'on_quantity_changed_in_cart', 20, 4 );
function on_quantity_changed_in_cart( $cart_item_key, $quantity, $old_quantity, $cart){
if( ! is_cart() ) return; // Only on cart page
//here stop price from been changed by default
}

Answer 1

Looking to "Disable Woocommerce cart line item quantity price calculation" answer thread, I found out I need to override an action hook to replace the final cost per line:
add_filter('woocommerce_cart_product_subtotal', [$this, 'filter_woocommerce_cart_product_subtotal'], 10, 4);
public function filter_woocommerce_cart_product_subtotal($product_subtotal, $product, $quantity, $cart){
$sub_value = 0;
foreach ($cart->cart_contents as $hash => $value) {
if ($value["product_id"] === wc_get_product($product)->get_id()) {
$sub_value = $value["wcform-custom_price"];
//wcform-custom_price is passed from when adding to the cart.
}
};
return wc_price($sub_value);
}
Now on the totals as well I overriden the following
add_action( 'woocommerce_calculate_totals', [$this,'custom_item_price'],20,1);
add_filter( 'woocommerce_calculated_total', [$this,"calculateFinalTotal"], 20, 2 );
public function custom_item_price( $wc_cart ) {
$cart_contents_total = 0;
foreach ( $wc_cart->get_cart() as $cart_item_key => $cart_item ){
$cart_contents_total += $cart_item["wcform-custom_price"];
}
$wc_cart->subtotal = $cart_contents_total;
}
public function calculateFinalTotal($total,$cart){
$cart_contents_total = 0;
foreach ( $cart->get_cart() as $cart_item_key => $cart_item ){
$cart_contents_total += $cart_item["wcform-custom_price"];
}
return $cart_contents_total;;///print_r($cart->get_cart());
}