Hi,
What you're showing it quite strange.
In the code of the plugins/hikashop/attachinvoice/attachinvoice/invoice.php you have this code by default:
i.imgur.com/20T8Jy5.png
The first half of that screenshot displays the price for each product and the second half of that screenshot displays the subtotal.
In both cases, you can see the same condition:
if($config->get('price_with_tax')){
...
}else{
...
}
This means that both areas will display either the amount with taxes or without taxes based on the same setting of the HikaShop configuration.
So with that default code, it's impossible to have one of them with taxes and the other without taxes since both have the same check.
What that means is that you must have changed the code in there in a way which makes both amounts inconsistent.
I don't know what you changed exactly though so I can't say what you should do.