When using the new stack, you no longer get automatic 301 redirection for wrongly cased URLs. For example, this is the proper URL on an eZ Publish 5.2 new stack site:

example.com/solutions/social-media-management

If you type in the correct characters but the wrong casing, it does not automatically give you a 301 redirect, as happens in legacy stack:

example.com/solutions/social-MEDIA-management