玩家在Chrome中不会倒退30秒，但可以在Firefox中使用

Question

我的代码无法在Chrome上运行，但在Firefox上运行正常。它不应该按照预期重绕30秒，而只是暂停Chrome上的播放器。知道我设置错了吗？

以下是我一直在使用的代码：

function jumpBySeconds(s) {
    try{playerInstance.seek(playerInstance.getPosition()+s);}catch(e){}
}

function displayButtons() {
    var playButton = document.getElementsByClassName('jw-controls jw-reset')[0];
    playButton.style.display = "block";
}

function hideButtons() {
    var playButton = document.getElementsByClassName('jw-controls jw-reset')[0];
    playButton.style.display = "none";
}

function addControlbarListeners(){
    var timer;
    var player = document.getElementsByClassName('jwplayer')[0];
    player.onmouseover = function(){displayButtons();};
    player.onmouseout = function(){hideButtons();};
    player.addEventListener("mousemove",function(){
        displayButtons();
        clearTimeout(timer);
        timer=setTimeout(mouseStopped,2000);
    });

    function mouseStopped(){                              
        hideButtons();
    }
}

function addPlayForwardAndBackwardButtons(){
    var playBack = document.createElement("img");
    playBack.id = "-30sb";
    playBack.setAttribute('class','jw-icon jw-icon-display jw-button-color jumpBackward jw-reset');  
    playBack.onclick = function(){
        jumpBySeconds(-30);
    }

    var middleBar = document.getElementsByClassName('jw-display-icon-container jw-reset')[0];
    middleBar.appendChild(playBack);
    middleBar.setAttribute('style',"background-color:rgba(0, 0, 0, 0.0); border: 0px; display: flex;");
    var playButton = middleBar.childNodes[1];
    middleBar.removeChild(playButton);
    middleBar.appendChild(playButton);

    var playForward = document.createElement("img");
    playForward.id = "+30sb";
    playForward.setAttribute('class','jw-icon jw-button-color jw-icon-display jw-reset jumpForward');
    playForward.onclick = function(){
        jumpBySeconds(30);
    }

    var middleBar = document.getElementsByClassName('jw-display-icon-container jw-reset')[0];  
    middleBar.appendChild(playForward);                    
    // set icon to center
    middleBar.style.width = "100%";
    middleBar.style.margin = "-1.0em auto 0";
}

playerInstance.onPause(function(){
    console.log("video stopped");
});

playerInstance.onPlay(function(){
    console.log("video playing...");
});

playerInstance.onReady(function(){            
    addPlayForwardAndBackwardButtons();
    addControlbarListeners();          
});