Different CSS is applied over the markers when opened in mobile device. Which enlarges the marker elements and the rendered positions appear incorrect.

The temporary fix is to reset the marker elements to their original size and position: 

 @media only screen and (-webkit-min-device-pixel-ratio: 2), only screen and (min-device-pixel-ratio: 2) {
     .k-map span.k-marker{
         width: 28px;
         height: 40px;
         margin: -40px 0 0 -14px;
     }
 }