Board Thread:General Discussion/@comment-25523075-20150827150157/@comment-957747-20150827152652

It actually is custom CSS on that wikia. This wikia has

in it's CSS. This change affects the size of the two s within the navbar which causes the 'tail' to be 1 pixel away from the rest of the border.

If you were to change the CSS to:

it would fix the issue.