Urgent help with ViewportFrames!

Basically i made a viewportframe with a character in it inside a GUI.
It shows the character and everything, the only problem is that its not updating.
Im changing the characters CFrame and nothing changes visually, i fixed this issue via using a WorldModel before but its not working this time.

Heres the explorer itself.
image

The characters CFrame is also getting updated btw.

Support very much needed.

here is a demo project with a character spinning inside a viewportframe
Viewport Demo.rbxl (48.1 KB)

image

local runService = game:GetService("RunService")

runService.Heartbeat:Connect(function(deltaTime)
	local cFrame = script.Parent.Dummy:GetPivot()
	cFrame *= CFrame.fromAxisAngle(Vector3.yAxis, deltaTime)
	script.Parent.Dummy:PivotTo(cFrame)
end)

If you read this article ViewportFrame GUI

there are some notes at the bottom