Pages being redirected to index.php

Server Config
1

Hello

All my pages are being redirected to index.php

The original page doesn’t even execute, it just redirected to index.php

The strange thing is it works if I put an ending forward slash e.g

www.website.com/hello.php (this will redirect without executing)
www.website.com/hello.php/ (this will execute)

why is this happening?

2

Do you have anything in your htaccess file? How is your site constructed? (Is it bult around a CMS?)