Checked="Checked" not working after target Checkbox was clicked once

I have the following GridView:

<asp:GridView ID="gvSpecificRights" runat="server" AutoGenerateColumns="false" OnRowCreated="gvSpecificRights_RowCreated" CssClass="mGrid" ShowHeaderWhenEmpty="true" ShowFooter="true">
    <Columns>
        <asp:BoundField DataField="ID" HeaderText="ID" SortExpression="ID" />
        <asp:TemplateField HeaderText="Name">
            <ItemTemplate><asp:Label ID="lblName" runat="server" Text='<%# Bind("Name") %>'></asp:Label></ItemTemplate>
            <FooterTemplate><asp:DropDownList ID="ddlAvailableUsers" runat="server"></asp:DropDownList></FooterTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Create" ItemStyle-HorizontalAlign="Center" FooterStyle-HorizontalAlign="Center">
            <ItemTemplate><asp:CheckBox ID="cbTickCreator" runat="server" Checked='<%# Eval("TickCreator") %>' CssClass="clicknext"></asp:CheckBox></ItemTemplate>
            <FooterTemplate><asp:CheckBox ID="cbFooterTickCreator" runat="server" CssClass="clicknext"></asp:CheckBox></FooterTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Read" ItemStyle-HorizontalAlign="Center" FooterStyle-HorizontalAlign="Center">
            <ItemTemplate><asp:CheckBox ID="cbTickViewer" runat="server" Checked='<%# Eval("TickViewer") %>'></asp:CheckBox></ItemTemplate>
            <FooterTemplate><asp:CheckBox ID="cbFooterTickViewer" runat="server"></asp:CheckBox></FooterTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:LinkButton ID="btnSave" runat="server" Text="<i class='fa fa-floppy-o'></i>" OnClick="btnSave_Click" CommandArgument='<%# Eval("ID")%>'/>
            </ItemTemplate>
            <FooterTemplate>
                <asp:LinkButton ID="btnAdd" runat="server" Text="<i class='fa fa-plus'></i> Hinzufügen" OnClick="btnAdd_Click" />
            </FooterTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

My goal is to automatically check and disable the Read-Checkbox, when the Create-Checkbox is clicked. Therefore I was able to create the following script:

<script>
    document.getElementById('Form').addEventListener('click', function (e) {
        if (e.target.parentElement.getAttribute("class") === 'clicknext') {
            if (jQuery(e.target).is(":checked")) {
                e.target.parentElement.parentElement.nextElementSibling.firstChild.setAttribute("checked", "checked");
                e.target.parentElement.parentElement.nextElementSibling.firstChild.setAttribute("disabled", "disabled");
            }
            else {
                e.target.parentElement.parentElement.nextElementSibling.firstChild.removeAttribute("checked");
                e.target.parentElement.parentElement.nextElementSibling.firstChild.removeAttribute("disabled");
            }
        }
    });
</script>

You may wonder why I was using .parentElement twice. This is because ASP.net will wrap a span around the checkbox, if you apply a css-class on it.

So the script works like a charm if i open the containing page and click the "Create"-Checkbox: The "Read"-Checkbox gets checked too and will be disabled. Unchecking the "Create"-Checkbox also works fine: The "Read"-Checkbox gets unchecked and reenabled.

BUT: As soon as I've checked or unchecked the "Read"-Checkbox manually once, the script won't work anymore. It's still able to enable/disable the "Read"-Checkbox and also sets the checked-attribute (seen over development-console), but the browsers (Firefox, Chrome) will not render it as checked.

Do you have any idea, what I'm doing wrong here? Thanks in advance!