Caller doesn't receive RemoteVideo

I make a call between user A(Sender) and user B(Receiver), user A receive onLocalVideoTrackReceive but dose not receive onRemoteVideoTrackReceive, and user B the opposite receive onRemoteVideoTrackReceive but dose not receive onLocalVideoTrackReceive!

Please help me to fix this, My code is below

override fun onCreate(savedInstanceState: Bundle?) {

       currentSession?.apply {
            addVideoTrackCallbacksListener(this@VideoCallFragment)
        }

    }

override fun onLocalVideoTrackReceive(session: RTCSession?, videoTrack: RTCVideoTrack?) {
        Logger.d(CALL_TAG, TAG, "onLocalVideoTrackReceive")
        if (isCurrentSessionClosed()) return

        mainHandler.postDelayed({
            videoTrack?.let { fillVideoView(localView, it, false) }
        },
                VIDEO_TRACK_INITIALIZE_DELAY
        )
    }

    override fun onRemoteVideoTrackReceive(session: RTCSession?, videoTrack: RTCVideoTrack?, p2: Int?) {
        Logger.d(CALL_TAG, TAG, "onRemoteVideoTrackReceive")
        if (isCurrentSessionClosed()) return

        mainHandler.postDelayed(
                {
                    videoTrack?.let { fillVideoView(opponentView, it, true) }
                },
                VIDEO_TRACK_INITIALIZE_DELAY
        )

    }

  private fun fillVideoView(videoView: RTCSurfaceView,
                              videoTrack: RTCVideoTrack,
                              remoteRenderer: Boolean
    ) {
        videoTrack.addRenderer(videoView)
        updateVideoView(videoView, remoteRenderer, RendererCommon.ScalingType.SCALE_ASPECT_FILL)
    }

    private fun updateVideoView(surfaceView: RTCSurfaceView,
                                mirror: Boolean,
                                scalingType: RendererCommon.ScalingType
    ) {
        surfaceView.setScalingType(scalingType)
        surfaceView.setMirror(mirror)
        surfaceView.requestLayout()
    }

fun startCall(context: Context, callType: Int, appointment: AppointmentDataCall) {
    val rtcCallType =
            if (callType == CALL_TYPE_VIDEO) RTCTypes.ConferenceType.CONFERENCE_TYPE_VIDEO
            else RTCTypes.ConferenceType.CONFERENCE_TYPE_AUDIO

   val occupants: ArrayList<Int> = ArrayList()
    occupants.add(appointment.calleeCcId.toInt())

    val session = RTCClient.getInstance(context)
            .createNewSessionWithOpponents(occupants, rtcCallType)

    val userInfo: MutableMap<String, String> = HashMap()
    userInfo[APPOINTMENT_ID] = appointment.appointmentId.toString()

    session.startCall(userInfo)

    RTCSessionManager.getInstance().currentCall = session

    Toast.makeText(context, "members = $occupants, callType = $callType", Toast.LENGTH_LONG).show()
}

ConnectyCube / android-messenger-app

Caller doesn't receive RemoteVideo #52