TabContainer - An activated tab still looks as inactive after updating AjaxControlToolkit from 15.1 to 16.1 about ajaxcontroltoolkit HOT 10 CLOSED

<script type="text/javascript">
    function removeDisabledClass() {
        var tabIDs = eval('<%= GetTabIDs()%>');

        setTimeout(function() {
            for(var i = 0; i < tabIDs.length; i++) {
                var header = document.getElementById(tabIDs[i] + "_tab");
                header.classList.remove("ajax__tab_disabled");
            }
        }, 50);
    }
</script>

<ajaxToolkit:TabContainer ID="tab_Container" runat="server">

    <ajaxToolkit:TabPanel ID="tb_A" HeaderText="OPTION_A" runat="server" OnClientClick="removeDisabledClass">
    </ajaxToolkit:TabPanel>

    <ajaxToolkit:TabPanel ID="tb_B" HeaderText="OPTION_B" runat="server" OnClientClick="removeDisabledClass">
    </ajaxToolkit:TabPanel>

    <ajaxToolkit:TabPanel ID="tb_C" HeaderText="OPTION_C" runat="server" OnClientClick="removeDisabledClass">
    </ajaxToolkit:TabPanel>

    <ajaxToolkit:TabPanel ID="tb_D" HeaderText="OPTION_D" runat="server" OnClientClick="removeDisabledClass">
    </ajaxToolkit:TabPanel>

</ajaxToolkit:TabContainer>

    <script type="text/javascript">
        var disabledTabIndex = 2; // can be set by external code

        function removeDisabledClass() {
            var tabIDs = eval('<%= GetTabIDs()%>');

            setTimeout(function() {
                for(var i = 0; i < tabIDs.length; i++) {
                    if(i === disabledTabIndex)
                        continue;

                    var header = document.getElementById(tabIDs[i] + "_tab");
                    header.classList.remove("ajax__tab_disabled");
                }
            }, 50);
        }
    </script>

...

<ajaxToolkit:TabPanel
    ID="tb_C"
    HeaderText="OPTION_C"
    runat="server"
    OnClientClick="removeDisabledClass"
    Enabled="false" />