Might be on my end then, I'll reinstall it and see if it works.

Unlikely. The folder locations are named what they should be called, and so is the soundfiles

Sound files MUST be named the exact same as the original sound file, and you must make folders named the exact same as the folder they are located in. Sounds also have to be the exact same length as the original sound to work properly(Not doing that gives it incorrect speed and pitch)

My guess is that its either a problem with the Steam servers, or the addon didn't install properly(There are sometimes an issue where it can't seem to find the addon, despite its installed)

Sadly doesnt seem to work, maybe something was renamed improperly?