The following script works and the map generates sometimes not all the times?

The map sometime generates randomly but doesn't other times, can I please get some help with the teleportation I used to store maps in lighting but now I switched it to ServerStorage.

01	-- Variables
02	 
03	    local player = game.Players:GetChildren()
04	 
05	    local maps = game.ServerStorage.Maps:GetChildren()
06	 
07	    local currentmap = game.Workspace:WaitForChild("CurrentMap")
08	 
09	    local chosenmap = script:WaitForChild("ChosenMap")
10	 
11	    local spawner = game.Workspace:WaitForChild("Spawn")
12	 
13	    local choices = {}
14	 
15	    function choosemap()
16	 
17	    for i = 1,#maps do
18	 
19	    if maps[i]:isA("Model") then
20	 
21	    table.insert(choices,maps[i])
22	 
23	    local picked = math.random(1,#maps) chosenmap.Value = choices[picked].Name
24	 
25	           end
26	       end
27	    end
28	 
29	    function loadmap()
30	 
31	    local map = game.ServerStorage.Maps:FindFirstChild(chosenmap.Value)
32	 
33	    map:Clone().Parent = currentmap
34	 
35	    end
36	 
37	    function deleteMap()
38	 
39	    for i,v in pairs(currentmap:GetChildren()) do
40	 
41	    if v:isA("Model") then
42	 
43	    v:Destroy()
44	 
45	          end
46	       end
47	    end
48	 
49	 
50	    function teleportPlayers()
51	 
52	    for i,v in pairs() do
53	 
54	    v.Character:FindFirstChild("HumanoidRootPart").CFrame = currentmap:FindFirstChild(chosenmap.Value).Spawn * CFrame.new(math.random(5,10),0,math.random(5,10))
55	 
56	       end
57	    end
58	 
59	    function teleportBack()
60	 
61	    for i,v in pairs(player) do
62	 
63	    v.Character:FindFirstChild("HumanoidRootPart").CFrame = spawner.Spawnlocation.CFrame* CFrame.new(math.random(5,10),0,math.random(5,10))
64	 
65	    end
66	 
67	    end
68	 
69	    while true do
70	 
71	    wait(3)
72	 
73	    choosemap()
74	    loadmap()
75	    wait(1)
76	    teleportPlayers()
77	    wait(10)
78	    deleteMap()
79	    teleportBack()
80	 
81	    end

Its probably because you have all the numbers there.