Dragging one image makes other image to drag

When i drag the right part of uploaded image in mask1 , than uploaded image in mask2 is dragging, but that should't happen....

Here is video link

Also if i upload image only in mask 1 and try to drag, the image will disappear , but if i upload images in both masks, than image will not disappear

video link2

Codepen : https://codepen.io/kidsdial/pen/PVJQrz

<input type="file" id="fileupa" />
<input type="file" id="fileupb" />

<div class="container">

<div class="minaimg masked-imga"   ondragover="onDragOver(event)"ondragover="onDragOver(event)" >
  <div draggable="true" ondragstart="onDragStart(event)" id="uploadedImg">
    <div class="minaimga">

      <img id="target_imga"  alt="">

      <div></div>

    </div>
  </div>
</div>

<div class="minaimg masked-imgb"   ondragover="onDragOverSec(event)"ondragover="onDragOver(event)" >
  <div draggable="true" ondragstart="onDragStart(event)" id="uploadedImg2">
    <div class="minaimgb">

      <img id="target_imgb"  alt="">

      <div></div>

    </div>
  </div>
</div>

</div>

<style>

.container {
    border: 1px solid #DDDDDD;
    width: 612px;
    height: 612px;
    position:relative;
    background:red;
}

.masked-imga

{

  -webkit-mask-image: url(http://139.59.24.243/ecom1/site/test/images/heart1.png);
  mask-image: url(http://139.59.24.243/ecom1/site/test/images/heart1.png);
  -webkit-mask-position: center center;
  mask-position: center center;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;  

  width: 259px;
  height: 278px;
  position: absolute;
    top: 221px;
    left: 23px;

}



.masked-imgb 
{

  -webkit-mask-image: url(http://139.59.24.243/ecom1/site/test/images/heart2.png);
  mask-image: url(http://139.59.24.243/ecom1/site/test/images/heart2.png);
  -webkit-mask-position: center center;
  mask-position: center center;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;  

    width: 416px;
    height: 388px;

    position: absolute;
    top: 111px;
    left: 173px;

}

.minaimga
{
  display: block;
  background-color: white;
  height: 278px;
}

.minaimgb 
{
  display: block;
  background-color: white;
  height: 388px;
}

</style>


<script>

fileupa.onchange = e => {
 target_imga.src = URL.createObjectURL(fileupa.files[0]);   
}

fileupb.onchange = e => {
 target_imgb.src = URL.createObjectURL(fileupb.files[0]);   
}

let prevX = 0, prevY = 0,translateX = 0, translateY = 0, scale = 1, zoomFactor = 0.1;

function onDragStart(evt) {
  if (evt.dataTransfer && evt.dataTransfer.setDragImage) {
evt.dataTransfer.setDragImage(evt.target.nextElementSibling, 0, 0);
  }
  prevX = evt.clientX;
  prevY = evt.clientY;
}

function onDragOver(evt) {
  translateX += evt.clientX - prevX;
  translateY += evt.clientY - prevY;
  prevX = evt.clientX;
  prevY = evt.clientY;
  updateStyle();
}

function updateStyle() 
{ 
let transform = "translate(" +translateX+ "px, "+ translateY + "px) scale("+scale+")"; 

if(document.querySelector('#uploadedImg img'))
document.querySelector('#uploadedImg img').style.transform = transform;
}

function onDragOverSec(evt) {
  translateX += evt.clientX - prevX;
  translateY += evt.clientY - prevY;
  prevX = evt.clientX;
  prevY = evt.clientY;
  updateStyleSec();
}

function updateStyleSec() 
{ 
let transform = "translate(" +translateX+ "px, "+ translateY + "px) scale("+scale+")"; 

if(document.querySelector('#uploadedImg2 img'))
document.querySelector('#uploadedImg2 img').style.transform = transform;
}




</script>

Edit

Is it because those two images overlapped horizontally & in vertically?

from Dragging one image makes other image to drag