Child view controller: FLEmbededViewController should have parent view controller Runner.FLEmbededViewController but requested parent is

Question

I'm trying to implement PictureInPicture mode in Flutter. For that I'm writing a native iOS view using Swift. When app goes to background and PiP mode starts, I have the following error:

Terminating app due to uncaught exception 'UIViewControllerHierarchyInconsistency', reason: 'child view controller:<Runner.FLEmbededViewController: 0x12503ca00> should have parent view controller:<FlutterViewController: 0x109021600> but requested parent is:<AVPictureInPictureViewController: 0x12bc5b5b0>'

My code:

@available(iOS 15.0, *)
class FLEmbededViewController: AVPictureInPictureVideoCallViewController, AVPictureInPictureControllerDelegate {
    
    var remoteVideoView: VTVideoView!
    var pipController: AVPictureInPictureController!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        initPiP()
        VoxeetSDK.shared.conference.delegate = self
    }
    
    func initPiP() {
        if #available(iOS 15.0, *) {
            if AVPictureInPictureController.isPictureInPictureSupported() {
                let sampleBufferVideoCallView = SampleBufferVideoCallView()
                view.addSubview(sampleBufferVideoCallView)
                sampleBufferVideoCallView.translatesAutoresizingMaskIntoConstraints = false
                let constraints = [
                    sampleBufferVideoCallView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
                    sampleBufferVideoCallView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
                    sampleBufferVideoCallView.topAnchor.constraint(equalTo: view.topAnchor),
                    sampleBufferVideoCallView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
                ]
                NSLayoutConstraint.activate(constraints)
                
                let pipContentSource = AVPictureInPictureController.ContentSource(activeVideoCallSourceView: remoteVideoView, contentViewController: self)
                
                pipController = AVPictureInPictureController(contentSource: pipContentSource)
                pipController.canStartPictureInPictureAutomaticallyFromInline = true
                pipController.delegate = self
            }
        }
    }
        
    func createRemoteVideoView() {
        remoteVideoView = VTVideoView()
        view.addSubview(remoteVideoView)
        remoteVideoView.translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate([
            remoteVideoView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            remoteVideoView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            remoteVideoView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            remoteVideoView.topAnchor.constraint(equalTo: view.topAnchor),
        ])
        
        remoteVideoView.backgroundColor = .black
    }
}

class SampleBufferVideoCallView: UIView {
    override class var layerClass: AnyClass {
        AVSampleBufferDisplayLayer.self
    }
    
    var sampleBufferDisplayLayer: AVSampleBufferDisplayLayer {
        layer as! AVSampleBufferDisplayLayer
    }
}

From what the error says I should change parent for FLEmbededViewController, but I don't really know how to do it.