Why aren't players taking damage from the Hitbox even when it spawns on them?

Rep.Events.Combat.OnServerEvent:Connect(function(Player, Action)
	if Action == "Light" then
		local hit = false
		local Character = Player.Character or Player.CharacterAdded:Wait()
		local Hitbox = game:GetService("ServerStorage").Hitbox:Clone()
		Hitbox.Parent = workspace
		local offset = Vector3.new(0,0,-2)
		Hitbox.CFrame = Character.HumanoidRootPart.CFrame*CFrame.new(offset)
	
		wait(.15)
		Hitbox.Parent = nil
		Hitbox.Touched:Connect(function(Touched)
			if not hit and not Touched:IsDescendantOf(Player.Character) and Touched.Parent:FindFirstChild("HumanoidRootPart") then
				hit = true
				Touched.Parent:FindFirstChild("Humanoid"):TakeDamage(10)		
					FX.Parent = workspace
					FX.CFrame = Touched.Parent.HumanoidRootPart.CFrame*CFrame.new(math.random(-10,5)/15,math.random(-10,5)/15,math.random(-10,5)/15)
			end
		end)
		wait(.2)
		FX.Parent = nil
	end
end)

You are using the touched function which only works when the player actually moves around. To fix this you can instead make the hitbox continously search for players inside of it and deal damage to them refer to this for more help https://devforum.roblox.com/t/how-do-you-check-if-the-player-is-in-certain-area/121163/11