smarthome > CameraStreamController > expirationTime is not working

Hello.

I need your help.

We are in the process of developing "smart home skills" to stream video through "Echo Show".

The video plays well.

However, I would like to automatically stop playback on an "ehco show" after a certain amount of time.

The response to a request for "Alexa.CameraStreamController" is:

{
    "event": {
        "payload": {
            "cameraStreams": [
                {
                    "protocol": "RTSP",
                    "expirationTime": "2018-02-23T09:58:32.29Z",
                    "authorizationType": "NONE",
                    "idleTimeoutSeconds": 30,
                    "audioCodec": "G711",
                    "uri": "rtsp://streamurl",
                    "resolution": {
                        "width": 1280,
                        "height": 720
                    },
                    "videoCodec": "H264"
                }
            ]
        },
        "header": {
            "payloadVersion": "3",
            "namespace": "Alexa.CameraStreamController",
            "name": "Response",
            "messageId": "......",
            "correlationToken": "........"
        }
    }
}

I have determined that "expirationTime" is the end time of the video.However, streaming continues to play even after the time has elapsed!"expirationTime" was setted in UTC time as required by "

https://developer.amazon.com/docs/device-apis/alexa-camerastreamcontroller.html#response".

The description of "expirationTime" is :

A date in ISO 8601 format indicating the expiration time of the stream. Should be specified in UTC.

please. help me.

I am waiting for your help.Thank you. Have a nice day :)