Camera Raw Brush tool problem

While in Camera Raw when I use the brush tool to apply selected adjustments, nothing happens even if I bump up the exposure all the way to the right or left. Nothing happens for the other functions also. But when I use the radial tool all the functions work perfectly. Anyone else facing this issue especially after the recent upgrade?

Attached is my camera raw window. I had painted the lion with the brush tool and the settings for the exposure, shadow, Whites & Blacks are all the way to the left, and nothing is being applied.