QML Mediaplayer + GStreamer freezes when repeatedly switching videos

onPositionChanged: {
    if ((mediaplayer.position >= mediaplayer.duration - 60)) {
        seek(0);
    }
}

import QtQuick 2.9
import QtQuick.Window 2.2
import QtMultimedia 5.9

Window {
    id     : mainWindow
    visible: true
    width  : Screen.desktopAvailableWidth
    height : Screen.desktopAvailableHeight
    color  : Qt.rgba(0, 0, 0.5, 1)    

    //Application running time label:
    Text {
        id     : time
        z      : 1000
        color  : "green"
        font {
            family   : "Arial"
            bold     : true
            pixelSize: 42
        }
        anchors {
            bottom: parent.bottom
            left  : parent.left
        }
    }    

//Time label updater:
    Timer {
        property var startTime: 0;  
        //Declared "var" to be able to operate this number with Date.getTime() result
        property bool stopped : true        

        id      : runningTime
        running : true
        repeat  : true
        interval: 500        

       Component.onCompleted: {
            time.text = timeConversion(0);
            startTime = new Date().getTime();
        }        
        onTriggered: {
            var elapsed = new Date().getTime() - startTime;
            time.text = timeConversion (elapsed);
        }        
        function timeConversion(millisec) {
            var d = new Date(parseInt(millisec, 10));
            return Qt.formatDateTime(d,"hh:mm.ss")
        }        
        function reset() {
            stopped   = false;
            startTime = new Date().getTime();
        }        
        function stop() {
            stopped   = true;
            time.text = timeConversion(0);
        }
    }    

    //List of 3 videos (1920 x 720 pixels)
    ListModel {
        id: videosModel        ListElement { videoName: "Beer_Bubbles.mov"; }
        ListElement { videoName: "Music.mov"; }
        ListElement { videoName: "Poker.mov"; }
    }    

//The delegate is an Item that wraps a VideoOutput and a MediaPlayer (the issue also happens if the delegate is a Video component)
    Repeater {
        property int currentVideo: 0        

        id   : videos
        model: videosModel        

        delegate: Item {
            width   : mainWindow.width
            height  : mainWindow.height            

            property alias videoPlaybackState: mediaplayer.playbackState;            
            //Proxy calls to the MediaPlayer video control methods
            function play  ()  { mediaplayer.play ()  }
            function pause ()  { mediaplayer.pause()  }
            function seek  (n) { mediaplayer.seek (n) }
            function stop  ()  { mediaplayer.stop ()  }            

            //Play the first video on application start up
            Component.onCompleted: {
                if(model.index === 0) {
                    mediaplayer.play();
                }
            }            

            VideoOutput {
                id      : videodelegate
                source  : mediaplayer
                fillMode: VideoOutput.PreserveAspectCrop
                anchors.fill: parent
            }            

            MediaPlayer {
                id: mediaplayer
                autoPlay      : false
                autoLoad      : true
                muted         : true
                source        : "file:///home/videos/" + model.videoName
                notifyInterval: 10                

                //Videos should loop forever, so few miliseconds before the end we reset them to 0
                onPositionChanged: {
                    if ((mediaplayer.position >= mediaplayer.duration - 60)) {
                        seek(0);
                    }
                }
            }
        }
    }    

    //Changes the video every 10 - 15 seconds
    Timer {
        id: videoChanger
        interval: (10*Math.random() + 5) * 1000
        running : true
        repeat  : true
        onTriggered: {
            videoChanger.interval = (10*Math.random() + 5) * 1000;
            nextVideo();
        }
    }    

    //Stops the current video and plays one of the 3 videos in the catalog
    function nextVideo() {
        //var nextID = (videos.currentVideo + 1) % videosModel.count; 
        //In case we want the videos to play consecutively
        
        var nextID =  Math.floor((Math.random() * 3));                
        //In case we want the videos to play in a random order
        if(videos.currentVideo > -1) {
            videos.itemAt(videos.currentVideo).stop();
        }
        videos.currentVideo = nextID;
        if (videos.itemAt(videos.currentVideo).videoPlaybackState !== MediaPlayer.PlayingState) {
            videos.itemAt(videos.currentVideo).play();
        }
    }}