When user clicks on e.g., bold text, comment, link, etc. the UI of RadEditor is not updated

Possible workaround is using the Window's Show event to attach a handler, that re-attaches the mouseup event of RadEditor with setTimeout:

<telerik:RadWindowManager runat="server" ID="RadWindowManager1">
    <Windows>
        <telerik:RadWindow runat="server" ID="RadWindow1" VisibleOnPageLoad="true" Width="800px" Height="500px" OnClientShow="OnClientShow">
            <ContentTemplate>
                <telerik:RadEditor ID="theEditor" runat="server" Width="100%" Height="100%" EnableComments="true">
                    <TrackChangesSettings Author="RadEditorUser" UserCssId="reU1"></TrackChangesSettings>
                    <Content>
                        <h2 class="titleText">RadEditor for ASP.NET AJAX</h2>
                        <p style="text-align: justify;"><span style="font-size: 19px; color: #4f6128;"><strong>RadEditor</strong></span>
                        is not simply an <strong>
                        <span class="reComment reU1" author="RadEditorUser" comment="comment 1" title="RadEditorUser: comment 1: 6/12/2015, 11:27:35 AM" timestamp="1434097655291">HTML</span></strong>
                        Editor.
                        <a href="http://www.telerik.com/products/aspnet-ajax/sharepoint.aspx">Link</a>.</p>
                    </Content>
                </telerik:RadEditor>
            </ContentTemplate>
        </telerik:RadWindow>
    </Windows>
</telerik:RadWindowManager>

<script type="text/javascript">
    function OnClientShow(sender, args) {
        var editor = $find("<%= theEditor.ClientID %>");

        window.setTimeout(function () {
            editor.attachInternalHandler("mouseup", function () {
                editor.raiseEvent("selectionChange");
            });
        }, 0);
                
    }
</script>