New
#11
I had the same problem with my HP 450 G4.
I went back to ver. 1709. All ok!
I updated the graphic driver automatically to ver. 23.20.16.5018, did the the update to 1803 again - and now I can change the brightness of the screen using the right panel. And the yellow mark on the graphic board is disappeared.
There is another Windows feature that can impact the function of drivers.
This would be trial and error to see if it has had an impact:
Turn On or Off Core Isolation Memory Integrity in Windows 10 | Windows 10 Tutorials (post #6)