I'm not saying it wasn't broke at some point in the past, but it doesn't appear to be broke right now. I just tested with a story and a chapter and it worked flawlessly. It updates about every 5 minutes so if you go to a chapter of your story, hit refresh 20 times, and then wait 5-10 minutes you should see the increase show up.
Regarding later chapters having higher numbers than previous chapters, that's usually people finding the site from the Internet and opening links not realizing it's not the first chapter. Sometimes site activity is higher and if your story post coincides with that period of time, or if you post and there is considerable time before the next author posts a story/chapter, you can see a far greater response because of that. As they say, out of sight, out of mind.