Basketball not bouncing properly in Lua in Roblox Studio (I am making a game in Roblox Studio)

Question

As the title clearly suggests, I am making a basketball game in roblox so I have recently been trying to make my basketball part, named "B-Ball" bounce in a continuous motion. This can be seen here with this code:

local bball = script.Parent

local function setPlayerJumpPower(player)
    local character = player.Character
    if character then
        local humanoid = character:FindFirstChildOfClass("Humanoid")
        if humanoid then
            humanoid.JumpHeight = 3
            print("Jump Power has been set to 3 for player " .. player.Name)
        end
    end
end

local function weldBallToHand(player)
    local character = player.Character
    if not character then return end

    local righthand = character:FindFirstChild("RightHand") or character:FindFirstChild("Right Arm")
    if not righthand then
        print("RightHand or Right Arm not found for player " .. player.Name)
        return
    end

    local wc = Instance.new("WeldConstraint")
    wc.Part0 = righthand
    wc.Part1 = bball
    wc.Parent = bball
    bball.Position = righthand.Position + Vector3.new(0, 2, 0) 
end


for _, player in pairs(game.Players:GetPlayers()) do
    setPlayerJumpPower(player)
end
game.Players.PlayerAdded:Connect(function(player)
    player.CharacterAdded:Connect(function(character)
        setPlayerJumpPower(player)
    end)
end)

local function animateBallContinuously()
    local initialPosition = bball.Position
    local bounceHeight = 6 
    local bounceTime = 0.5 

    local tweenService = game:GetService("TweenService")
    local upTweenInfo = TweenInfo.new(bounceTime, Enum.EasingStyle.Quad, Enum.EasingDirection.Out)
    local downTweenInfo = TweenInfo.new(bounceTime, Enum.EasingStyle.Quad, Enum.EasingDirection.In)

    local goalPositionUp = initialPosition + Vector3.new(0, bounceHeight, 0)
    local goalPositionDown = initialPosition

    local upTween = tweenService:Create(bball, upTweenInfo, {Position = goalPositionUp})
    local downTween = tweenService:Create(bball, downTweenInfo, {Position = goalPositionDown})

    upTween.Completed:Connect(function()
        downTween:Play()
    end)

    downTween.Completed:Connect(function()
        wait(0.1)
        upTween:Play()
    end)
    upTween:Play()
end

bball.Touched:Connect(function(hit)
    if not hit then return end
    local character = hit.Parent
    if not character then return end
    local player = game.Players:GetPlayerFromCharacter(character)
    if not player then return end

    print("Touched part: " .. hit.Name)
    print("Character: " .. character.Name)
    weldBallToHand(player)
    animateBallContinuously()
end)
bball.Anchored = false
bball.CanCollide = true
bball.Velocity = Vector3.new(0, -50, 0)
print("Ball initial position: " .. tostring(bball.Position))

When I try and run it, there is no error (so clearly a logic error) but the ball slowly rises up and instead of bouncing just sort of levitates and hovers about. I expected it the bounce up and down. Do you have any idea what could be causing this?

Many thanks in advance