Awesome, Whatevergreen basically fixed the glitch. Only appears for 0.2 seconds which doesn't bother me.
For the brightness controlles, I use FN+F4 and FN+F5 which are the native keys. If I use the preferences it works fine. I have attached a video
https://photos.app.goo.gl/ckHj6oi6MGn8bLYg7
In the video you can see I press brightness up once, it then continues to be held without me touching anything until I press brightness down. After that the brightness keys do nothing until I reboot.