As per this post your communities should show top 5 sites by reputation, but it show more than that, is it normal or bug ? I checked all my sites it list 6 sites and one of the site showing 7 sites- please see the screenshot below.
It's a bug; it's supposed to only show 5 sites, but there are some goblins in our code making a different number of sites appear for some people.
We'll be evicting the goblins shortly.
Fun fact: order of operations matters! The goblins have been appropriately chastised, and a fix is incoming.
Note that the old list is still going to be cached for most folks for a while, but eventually it will catch up and update.