This is the After Effects forum. You should move your post to Lightroom.
I moved this post to the Lightroom forum, but you should really provide more information if you want help. A screen recording of what's "not working" would be incredibly helpful, or even more description.
Is your brush Opacity, Flow, or Density too low? Are you drawing a brush, but not changing any adjustment settings? Was this workign in a previous update for you?
A little more information or a screenshot of your Adjustment Brush panel would go a long way.