Advanced Dynamic Pricing for WooCommerce – negative discount does not work

Hi, I use the plugin Advanced Dynamic Pricing for WooCommerce, mainly to create discounts for quantaties, but I also use it to increase prices in small amounts for a special use and I deal this buy adding a fixed negative discount. But recently I’ve discovered that it no longer works, it doesn’t add the price. How can I fix this? Is it a bug from the last update?