Rainbow Trail Gamepass only works on one player at a time. Any help?

-- took me 5 mins lol
local gamePassId = 10498381
local RainbowTrail = game.ServerStorage.RainbowTrail
local function UserOwnsGamePassAsync(player, gamePassId)
	local hasGamepass = false
	local MarketplaceSuccess, MarketplaceErr = pcall(function() -- Wrap in a pcall because errors can come up.
		hasGamepass = game:GetService("MarketplaceService"):UserOwnsGamePassAsync(player.UserId, gamePassId)
	end)
	if MarketplaceSuccess then
		return hasGamepass
	else
		warn("Error on MarketplaceService:UserOwnsGamePassAsync: ", MarketplaceErr)
		return false
	end
end
local function attach(ch, att)
	for i = 1, #att do
		local off = tostring(i-1)
		local attachment = Instance.new("Attachment")
		attachment.Parent = att[i]
		attachment.Name = "TrailAttachment-"..off
		ch["Attachment"..off] = attachment
	end
	ch.Parent = att[1]
end
local Players = game:GetService("Players")
Players.PlayerAdded:Connect(function(plr)
	plr.CharacterAdded:Connect(function(char)
		if UserOwnsGamePassAsync(plr, gamePassId) then
			attach(RainbowTrail:Clone(), {char.Head, char.HumanoidRootPart})
		end
	end)
end)