Where are the brightness controls?
Solution 1:
I took a moment searching the problem in the internet, one of the proposed solutions :
sudo add-apt-repository ppa:apandada1/brightness-controller
sudo apt update
sudo apt install brightness-controller
Normally, after this, you will have the brightness controller. You can find it under Settings>Power menu or search it in Dash.
Solution 2:
This was fixed in a recent update. I am not sure which package was updated to fix this. So yeah I'm closing this question