Reputation and badges (known as 'rep' for the purposes of this post) seem to be confusing on Meta SE sites:
Rep is not always the same between SE Main and SE Meta. Presumably this is due to caching.
Rep means nothing on SE Meta but is still shown just like on the Main site, suggesting to the user that it behaves the same way. However up/down voting does not affect the score which is not expected.
Rep does operate as expected on this SO Meta, leaving users more confused if they stumble across here.
I found these issues myself when first starting on Meta Stack Exchange sites, and just had another user report the same thing.
Would it be possible to hide rep on Meta SE sites, or at least make it visually obvious that it's a different animal?