problem slash at the end of url

Hello,

I'm trying this url on my project:  http://localhost/ci4.0.4/about   
Result: works fine

but when I added slash at the end of the url like:
http://localhost/ci4.0.4/about/

Result: it redirect to http://localhost/about

This is my setup:
$baseURL = 'http://localhost/ci4.0.4/';

I'm using: wamp server under Windows10

any advice, Thanks in Advance,