When a player is invisible with a invisibility potion, their nametag is showing. Please make a part in the config where you can choose if you want the nametag to be visible or not when being invisible. Thanks!

Example: Link to picture

This is an issue with 1.8 Minecraft. This was fixed in 1.9 (or at least that's what Mojang claimed.) If you are not using 1.8, please reopen this issue - we'll look into it further.