why is the script causing spam even with a Debounce on it?

Hello. Try using a table. Try this:

local player = game.Players.LocalPlayer
player.CharacterAdded:Wait()
db = false
local cointouchevent = game:GetService("ReplicatedStorage"):WaitForChild("Slotdata"):WaitForChild("CoinDestroy")
local hum = player.Character:WaitForChild("Humanoid")
pointsvalue = player:WaitForChild("leaderstats"):WaitForChild("Points")

    local sound = Instance.new("Sound",player.PlayerGui)
    sound.SoundId = 'rbxassetid://203620899'
    sound.MaxDistance = 100
    sound.Volume = 4

local touchedCoins = {}

hum.Touched:Connect(function(hit)
            if hit.Name == "Coin" then
        if db == false then
    db = true
    
    for i, v in pairs(touchedCoins) do
          if v = hit then
		return nil
	  end
    end

    table.insert(touchedCoins, 1, hit)
    print("Somar money")    
    sound:Play()
    pointsvalue.Value = pointsvalue.Value + 1
hit:Destroy() 
db = false
end
end
end)

coroutine.wrap(function()
	while wait(5) do
		for i = 1, #touchedCoins do
			table.remove(touchedCoins, i)
		end
	end
end)

When a coin is touched, it gets inserted into the table. Then every 5 seconds the coin in the touchedCoins array gets removed. Please accept and upvote this answer if it helped.