Permissions always return true

Hey,
since months my plugin has alwys problems with permissions. I use this simple method to check if a player has a permissions:

Code:

//Checks permission
            if(plugin.getPermission().has(sender, "dynshop." + permission.toLowerCase(Locale.ENGLISH)) || sender.hasPermission("dynshop." + permission.toLowerCase(Locale.ENGLISH))){
                return true;
            }else{
                if(sendMessage) player.sendMessage(plugin.getName() + "You don't have the permission to do this.");
                return false;
            }

plugin.getPermissions() returns the permissions api from Vault.
Sometimes it works, sometimes not. Now it always return true. If I enable PEX debug mode I can see, that PEX not even reveives a request to check the permissions. A few hours ago it worked -.-Tested it with PermissionsEX and bPermissions, always the same...

 

you're op

 

Sometimes it is the easy things -.-