CrossPost w/ AOUSD forum: Autoplay stage metadata not being acknowledged RealityView (RCP Bundle)

The Apple documentation seems to say RealityKit should obey the autoplay metadata, but it doesn't seem to work. Is the problem with my (hand coded) USDA files, the Swift, or something else? Thanks in advance.

I can make the animations run with an explicit call to run, but what have I done wrong to get the one cube to autoplay?

https://github.com/carlynorama/ExploreVisionPro_AnimationTests

import SwiftUI
import RealityKit
import RealityKitContent

struct ContentView: View {

    @State var enlarge = false

    var body: some View {
        VStack {
            //A ModelEntity, not expected to autoplay
            Model3D(named: "cube_purple_autoplay", bundle: realityKitContentBundle)
            //An Entity, actually expected this to autoplay
            RealityView { content in
                if let cube = try? await Entity(named: "cube_purple_autoplay", in: realityKitContentBundle) {
                    print(cube.components)
                    content.add(cube)
                }
            }
            //Scene has one cube that should auto play, one that should not.
            //Neither do, but both will start (as expected) with click.
            RealityView { content in
                // Add the initial RealityKit content
                if let scene = try? await Entity(named: "Scene", in: realityKitContentBundle) {
                    content.add(scene)
                }
            } update: { content in
                // Update the RealityKit content when SwiftUI state changes
                if let scene = content.entities.first {
                    
                    if enlarge {
                        for animation in scene.availableAnimations {
                            scene.playAnimation(animation.repeat())
                        }
                    } else {
                        scene.stopAllAnimations()
                    }
                    let uniformScale: Float = enlarge ? 1.4 : 1.0
                    scene.transform.scale = [uniformScale, uniformScale, uniformScale]
                }
                
               
            }
            .gesture(TapGesture().targetedToAnyEntity().onEnded { _ in
                enlarge.toggle()
            })

            VStack {
                Toggle("Enlarge RealityView Content", isOn: $enlarge)
                    .toggleStyle(.button)
            }.padding().glassBackgroundEffect()
        }
    }
}

No autospin meta data

#usda 1.0
(
    defaultPrim = "transformAnimation"
    endTimeCode = 89
    startTimeCode = 0
    timeCodesPerSecond = 24
    upAxis = "Y"
)

def Xform "transformAnimation" ()
{
    def Scope "Geom"
    {
        def Xform "xform1"
        {
            float xformOp:rotateY.timeSamples = {
               ...
            }
            double3 xformOp:translate = (0, 0, 0)
            uniform token[] xformOpOrder = ["xformOp:translate", "xformOp:rotateY"]

            over "cube_1" (
                prepend references = @./cube_base_with_purple_linked.usd@
            )
            {   
                double3 xformOp:translate = (0, 0, 0)
                uniform token[] xformOpOrder = ["xformOp:translate"]
            }
        }

With autoplay metadata

#usda 1.0
(
    defaultPrim = "autoAnimation"
    endTimeCode = 89
    startTimeCode = 0
    timeCodesPerSecond = 24
    autoPlay = true
    playbackMode = "loop"
    upAxis = "Y"
)

def Xform "autoAnimation"
{
    def Scope "Geom"
    {
        def Xform "xform1"
        {
            float xformOp:rotateY.timeSamples = {
                ...
            }
            double3 xformOp:translate = (0, 0, 0)
            uniform token[] xformOpOrder = ["xformOp:translate", "xformOp:rotateY"]

            over "cube_1" (
                prepend references = @./cube_base_with_purple_linked.usd@
            )
            {
                quatf xformOp:orient = (1, 0, 0, 0)
                float3 xformOp:scale = (2, 2, 2)
                double3 xformOp:translate = (0, 0, 0)
                uniform token[] xformOpOrder = ["xformOp:translate", "xformOp:orient", "xformOp:scale"]
            }
        }
    }
}