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;
     }
 }

The following error occurs after the partial post back:

Error: Sys.InvalidOperationException: Two components with the same id 'RadMap1' can't be added to the application.


You can resolve this by using the RadScriptManager instead of native ScriptManager control.

Replicable in Overview demo - https://demos.telerik.com/aspnet-ajax/map/examples/overview/defaultcs.aspx?skin=Material

In the Kendo/ASP.Net Map add the option for a legend with distance scale that updates on zoom level.  See attached image for placement and function 

When the Map position is not on the top of the page, creating a new marker via the OnClick event argument location, the marker is not correctly positioned.

This feature would be useful when the bound markers are dynamically changing. With such functionality the end-user will be able to automatically examine all bound markers and would not need to pan or zoom. 

This error is due to missing configuration option for the Bing layer. The settingsUrl property of layer options could be used to fine tune the URL and modify it to request data from SSL enabled URL and resolve the mixed content issue.

To resolve the issue, you can configure this property on the OnInitialize event and the options of the Map, exposed by the arguments:

<telerik:RadMap runat="server" ID="RadMap1">
    <LayersCollection>
        <telerik:MapLayer Type="Bing" Key="YOUR BING KEY"></telerik:MapLayer>
    </LayersCollection>
    <ClientEvents OnInitialize="OnInitialize" />
</telerik:RadMap>
 
<script type="text/javascript">
    function OnInitialize(sender, args) {
        var options = args.get_options();
        options.layers[0]["settingsUrl"] = "https://dev.virtualearth.net/REST/v1/Imagery/Metadata/#= imagerySet #?output=json&jsonp=bingTileParams&include=ImageryProviders&s=1&key=#= key #";
        args.set_options(options);
    }
</script>