VM 2.6.12.
If apply calculation rule it stay the same, it show not changed price in custom field.
When select custom field it calculate discount on custom field in final price... It calculate correct but it not show discounted price for custom field. This is a bug... this lie customer!
In this topic I want to report and missed must have option.
Apply calculation rules only for product price / Apply calculation rules only for product price + custom fields prices.
For some products it is not correct to apply 50% discount for additional options (custom fields)