AutoExposure problem

Hello sometimes I have problems with the Auto Exposure, sometimes I get the right exposure but other times I get totally burned in the same file, camera.... Here first I got it right, but then got totally burned... How can I fix this? or may be I´m doing Something Wrong!!! 3ds max 2018 - vray 3.60.04 -SR 2.50... Tried to re open my 3ds max File and still can´t fix it!!!