Additional fixed cost on on shipping problem

Hi I have a problem with shipping. I have set my shipping to set additional fixed cost when an order is above 39.99 to 0 so that delivery is free.
Everything works fine until I add an item which has discount.

e.g I have items that cost 47euros before discount and with dicount the total is 42 euros. Shipping should be free based on the rule I added above 39.99 to be free but shipping is charged.

It is strange.

Thanks in advance.

I think I found the problem but don't know how to resolve it.

My order subtotal before tax is 41.14. I have discount of 10% which gives total 36.93 before tax. After tax price is 42.90.
I have set the rule when order subtotal is 40euros shipping is free. It seems that subtotal does not take into account the tax. so the subtotal is 36.93 before the tax and the free shipping is not applied.

How to fix this?

Please help

Are you using Discount of type "Assigned to shipping"?  Which Rule/requirement plugin are you using?

Iam using discount applied to product.
I am using Manual( Fixed by weight or total) plugin

There is a shipping settings  under the Free shipping over 'X' option:
  Calculate 'X' including tax  

(If you don't see it, what version of nopCommerce are you using?)

I cant use that settings because based on country I dont have free delivery.

It's going to require customization, because the Fixed or By Weight Total shipping provider (plugin) does its own subtotal calculation with individual items, to eliminate items/products that are marked 'free shipping'.

Or, you can use Shipping Director which has several built-in variables such as

$SubTotalWithoutDiscounts
$SubTotalWithDiscounts
$SubTotalWithoutDiscountsInclTax
$SubTotalWithDiscountsInclTax

You could have Shipping Director call your existing Fixed or By Weight configuration, and then use a Surcharge Expression to negate the rate (similar to this example).   For example:

Option
Shipping
true
Shipping.FixedByWeightByTotal
Country = "GB" and [$SubTotalWithDiscountsInclTax] > 39.99 ? -[$Rate] : 0


(If you use the above, then remove any Fixed or By Weight configuration rules that, as you put it, "set additional fixed cost when an order is above 39.99 to 0").