Vray frame buffer Correction control Highlight burn Not working

Hi, as the title says, while rendering through Solid Rocks frame buffers Highlight burn acts as if the image is 8bit, it darkens the hole image, it does not reduse the intensity of the burned parts. It is a very important feature of the buffer. Is it just a button I havent clicked or something like that, thank you

Im really sorry, I found it, for it to work the Clamp button must be unchecked...