https://imgur.com/a/sbf5QUq
You have to swipe to show the navigation bar.
1st pic shows what it was like before the update. Basically there's empty space to the left and right, and the navigation bar fits in the right space nicely and doesn't overlap (couldn't find a screenshot that shows it)
2nd pic shows the updated version and the 3rd shows the updated version with the navigation bar swiped in and it overlaps the right inventory buttons. The curved screen also makes tapping the batt icon a little harder.
Also when you have another application like Youtube in pop-up view, the navigation will pop up automatically, just transparent and allows you to press Back.
It worked well pre-update since the navigation bar would always fit nicely without overlapping but, as shown in this image, now that transparent bar overlaps too. (The bar is there but not very visible because it overlaps when it used to be on black empty space)
So instead of hitting the inventory icon or whatever you end up pressing the Home button.
It's not a huge deal, just annoying to have something that we're already used to be changed in such a way, with no toggle or option to keep the old UI. Note 9s don't even have notches so i'm not sure why the update affected them in the first place. The old layout was much more ergonomic imo.