RealityKit: VideoMaterial causing odd outline around transparent video?

I have a transparent video that I created as a test. It's an mov file that was exported as HEVC 265, which means it has transparency as a background.

I am using it for VideoMaterial in RealityKit, which now has support for transparent videos.

I just loaded it like you would think:

private static var playerLooper: AVPlayerLooper? = nil // property of class

let video = AVURLAsset(url: Bundle.main.url(forResource: "transparentVideo", withExtension: "mov")!)
        let playerItem = AVPlayerItem(asset: video)
        
        let queuePlayer = AVQueuePlayer()
        playerLooper = AVPlayerLooper(player: queuePlayer, templateItem: playerItem)
        let material = VideoMaterial(avPlayer: queuePlayer)
        
        let myMesh = MeshResource.generatePlane(width: 300, depth: 90)
        let myModel = ModelEntity(mesh: myMesh, materials: [material])
        myModel.position = .init(x: 0, y: -22.48, z: 75)
        
        queuePlayer.play()

There is one issue.

When I load the material in, it has a gray outline around it:

Everything that is the edge of transparency has a gray background, which is really odd. I've tried multiple sources and ways of exporting/making videos and I'm pretty sure it is not my video. I think it is something with RealityKit.

How can I get rid of this?

(the yellow circle is the only content in the video, it was just a test)