New
#11
Here is one post I saw.
Windows 10 1809 - Missing Display Options
They said they did clean and got same results.
More
https://answers.microsoft.com/en-us/windows/forum/windows_10-update/windows-brightness-issue-after-the-1809-update/2a1689ae-5625-4679-9ab7-3f754cb8111b?page=4
and pretty sure I saw comments about Adaptive Brightness in that very long 1809 thread.
Is this what you meant Do tell?