Badge Isn't Being Given Properly?

I have a badge script that activates when you complete a wave in my tower defense game. This is the script:

function KilledBigBoss(ID)
    BadgetId = ID
game.Players.PlayerAdded:connect(function(p)
wait(0.1)
b = game:GetService("BadgeService") 
b:AwardBadge(p.userId,BadgetId)
end)
end

However, it seems to only work when you play singleplayer. Anyone have any pointers?