Why do my character animations and handle's not work on my custom character?

When I put a StarterCharacter in the StarterPlayer, the basic R6 animations load and the handle of my tool works. But when I load in a custom character through a script, the animations and handle don't work. The arm which I hold my tool with stays down vertically.

This is how I load in my character:

local RepStore = game:GetService("ReplicatedStorage") 
local ChoiceEvent = RepStore:WaitForChild("ChoiceEvent")
local Characters = RepStore:WaitForChild("Characters")
ChoiceEvent.OnServerEvent:Connect(function(Player)
local CharSelect = math.random(1,7)
print(CharSelect)
    if CharSelect == 1 then
        local Character = Characters:FindFirstChild("Character1")
        if Character then
            local NewCharacter = Character:Clone()
            NewCharacter.Parent = game.Workspace

            Player.Character = NewCharacter
        end
    end
    if CharSelect == 2 then
        local Character = Characters:FindFirstChild("Character2")
        if Character then
            local NewCharacter = Character:Clone()
            NewCharacter.Parent = game.Workspace

            Player.Character = NewCharacter
        end
    end

-- You get the rest!

The characters that I load in are exactly the same as the StarterCharacter and have the same settings as the starter character. Except that the custom characters wear a hat. What is the problem and what could be the fix?

Thank you in advance!

Edit:

I used HumanoidDescription to load the characters (R6 in this case for me.) I first defined the HumanoidDescriptions and then load the existing character with a humanoid description.

            NewCharacter.Parent = game.Workspace

            Player.Character = NewCharacter
            local humanoidDescription = RepStore:WaitForChild("HumDesc"):WaitForChild("Char2Desc")
            Player:LoadCharacterWithHumanoidDescription(humanoidDescription)
        end
    end