Below is the website that I am developing right now.
When I test it on my Android smartphone with the Chrome browser, the address bar does not hide when I scroll down.
(Same with Safari browser on iPhones.)
It seems like most websites have this behavior; for example, https://www.apple.com .
Here, it says that the address bar should hide by doing window.scrollTo(0,1); which probably indicates that the address bar hiding when the window scrolls down is the "default" behavior.
I started developing my website using this template as a starting point, and it seems to behave correctly.
Any help is greatly appreciated.