The hide navigation bar button is missing in Android Pie. Is there any way to get it back?

[Android Central Question]

I updated to Android 9 last night on my Galaxy S9+. After updating, I noticed the hide navigation bar button is now missing. It wouldn't be such a big deal if the navigation bar was see-through like it was in Android 8, but now it is now solid in most apps, which is annoyingly reducing the viewable screen size. I am aware of the Gestures setting that has been added to the Navigation Bar settings in Android 9. This option still leaves visible lines at the bottom of the screen. The hide button was a much more viable option for full screen visibility. Is there any way to hide the navigation bar in Android 9?

 

[Naux]

1. Settings > Display > Navigation bar
2. Select Full screen gestures
3. Turn off Gesture hints
This removes the navigation bar to allow full screen view. Then you can use the swipe gestures to navigate.

 

[raindroptree]

1. Settings > Display > Navigation bar
2. Select Full screen gestures
3. Turn off Gesture hints
This removes the navigation bar to allow full screen view. Then you can use the swipe gestures to navigate.

The full screen gestures option does not exist in my settings. Also, no gesture hints or anything. This is what mine looks like in the photo.
Also, the navigation bar button is disabled for some reason, shown in the other photo from the swipe down menu. I used to be able to simply click that button to toggle on or off the navigation bar, now it doesn't work, it is unclickable. What should I do to get rid of the navigation bar?