Spigot 1.8 Essentials /fly permission issues? (Minecraft Server)?

I have recently updated my Minecraft 1.7.10 server to 1.8. I downloaded Spigots version of Essentials {1.8 version} since Essentials has yet to updated their official plugin. I'm having permission issues with this essentials though. Many people on the server have bought fly mode but the permission isn't working. I use GroupManager for permissions and use the command /manuaddp [player] essentials.fly
It says I have given the player that permission, but each time I do, every play still says they can't do /fly (it says the 'you do not have permission' msg) Does anyone have any ideas on why this is happening or what I need to do instead to fix it? All the other permissions are working (besides /feed which many players need that one as well)