When adding a background to comments for some reason it's deciding to chop off a part of the @ sign. The first grayish @ sign is what it should look like.
If I remove the background color from comments it no longer does this. Also on a longer actual file, with multiple doc blocks, for some reason if I scroll the buffer past the beginning of the first doc block they would fix themselves until I scrolled back up. This wasn't entirely reproducable though (well it was in that file), but just adding white space to the buffer shown above to make it scrollable didn't produce the same behavior.