Windows 10: How to remove white line on Explorer dark theme

Does anyone know how to hide this white line? it's feel doesn't right for me

when i move the cursor to that line, the cursor change it's icon to vertical up/down, but i can't drag it, kinda fixed height.




:)

 

Dark Theme for File Explorer.

I waited exactly 9 years since Windows 7 released for Dark Theme to be used on the File Explorer and i feel hyped about Dark Theme can be used when you update your windows to version 1803 few weeks ago when i read it on article. My friend already got
their File Explorer themed black, and i already updated it to version 1803 as they say it will works. But why my file explorer theme is still white even though its on version 1803 and already changed the theme to dark? Thank you.

 

File explorer dark theme not applying properly

Since the implementation of Dark theme, I've been a bizarre white tool bar, it originates from the white theme but apparently it doesn't change when I apply the dark theme.
You can see what I mean here.

An interesting remark I have to make is that when launching File Explorer shortly after signing in from a reboot, the File Explorer dark theme is applied correctly.

I have tried from uninstalling applications to testing in safe mode, and even that was futile, as the behaviour was the same.

I'm at the end of my rope, your help would be appreciated.

Note: The dark theme is also applied properly when launching file explorer through shell.

 

File explorer in dark theme gone!

There was an option for choosing dark mode. I followed both suggestion above to the letter. But it did not fix the problem. Only Explorer is white. Which was the behavior before 1809.