How to databind in radzen radzen tooltip

Question

I have button which opens Html tooltip like this:

@inject TooltipService _tooltipService

<RadzenButton @ref=_deleteButton Click="OpenTooltip" />

@code {
    [Parameter]
    public RenderFragment ChildContent { get; set; } = null!;

    private RadzenButton _deleteButton = null!;

    private void OpenTooltip()
    {
        _tooltipService.Open(_deleteButton.Element, _ => ChildContent, new TooltipOptions { Duration = null });
    }
}

When button is clicked, it correctly renders content, however if ChildContent contains databindings, they are not bound. For instance:

<ButtonWithPopup>
   Value is @_val.ToString()
   <RadzenButton Text="ClickME" Click="Callback"/>
</ButtonWithPopup>

   Value outside is @_val.ToString()
@code
{
    private bool _val;
    private async Task Callback()
    {
        _val = true;
    }
}

This will print Value is false, Value outside is true.

How can I force tooltip to be rerendered when its content changes?