Why MinionThinker spawning only one time What is the problem?

I am trying to thread a function for each minion in the world. But it only seems to thread once. I don't really know what the problem is.

here is how it works.

--server script
local function minionThinker (plr,minion)
	--setup functions
	while true do
	if not minion then return end
	wait(0.01)
	end
end)
------------------------------
players.PlayerAdded:Connect(function(plr)
	if not plr then return end
	local playerMinions = Minions:WaitForChild(plr.Name)
	for i,minion in pairs(playerMinions:GetChildren())do
		spawn(minionThinker(plr,minion))--> coonects the minion thinker function
		print("minion added")
	end
	
	playerMinions.DescendantAdded:Connect(function(des)
		spawn(minionThinker(plr,des))
		print("Minion added")
	end)
end)

I will also show you how the adding of the minions work

--module script
	function module.CreateMinion (plr,minionName)
		if ServerMinions:FindFirstChild(minionName)then
			if plr then
				for I = 1,10 do 
					local serverCopy =  serverMinions:FindFirstChild(minionName):Clone()
					serverCopy.Parent = minionFolder:FindFirstChild(plr.Name)
						
					wait(0.001)
					print(#minionFolder:GetChildren())--> only prints "1" ten times
				end
			end
		end
	end