/back permission don't work

[WareZ57]

Hello I use your plugin recently and I'm setting permissions (Luckyperms) but currently I'm having a problem with one of them mainly the command of the /backI have put the permissions in the files or via the game it does not work.

uc.back.back.base
uc.back.back.ondeath
find : https://github.com/Bammerbom/UltimateCore/blob/master/docs/permissions.md

1~ https://image.noelshack.com/fichiers/2018/38/5/1537519112-aaaaacapture.png
2~ https://image.noelshack.com/fichiers/2018/38/5/1537519112-ccccccapture.png
3~ https://image.noelshack.com/fichiers/2018/38/5/1537519112-bbbbcapture.png

Sponge Forge - Lasted version / UC Lasted version
NO ERROR

Thanks you

(Sorry for my bad english)