I am facing the same problem, there are no adaptive settings option awailable. In my laptop, the brightness keeps on increasing to 100 unnecessarily. I literally had a battle with laptop to minimize the brightness, but after few seconds it turns back to 100% and that's irritating.
Please help..!! I have lots of work to do... And with that brightness its impossible to work, atleast suggest me any third party aap to control the brightness... Please help...