QueryableExtension.ToFilterString blank on only IEnumerable

When using RadzenDataFilter with a IEnumerable<int> filter value, .ToFilterString() and ToODataString() both return a blank string.

As soon as a regular string-based filter is added, it generates the values.

The below code should reproduce the issue.

@page "/dataFilterBug"

<RadzenButton Text="IEnumerable Only Filter" Click="EnumerableFilter" />
<RadzenButton Text="Text Only Filter" Click="TextFilter" />
<RadzenButton Text="Mixed Filter" Click="MixedFilter" />
<RadzenDataFilter @ref="dataFilter" TItem="Demo" ViewChanged="@(()=>StateHasChanged())" >
    <Properties>
        <RadzenDataFilterProperty Type="@typeof(string)" Property="@nameof(Demo.Title)" />
        <RadzenDataFilterProperty 
        Type="@typeof(IEnumerable<int>)" 
        Property="@nameof(Demo.DemoValue)"
        FilterOperator="FilterOperator.Contains"
        FilterOperators="@(new [] { FilterOperator.Contains, FilterOperator.DoesNotContain})">
            <FilterTemplate Context="field">
                <RadzenDropDown @bind-Value="@(field.FilterValue)"
                Style="width:100%;"
                Data="@(new List<int> { 1, 2, 3, 4, 5 })"
                AllowClear="true"
                Multiple="true" />
            </FilterTemplate>
        </RadzenDataFilterProperty>
    </Properties>
</RadzenDataFilter>

@if (dataFilter != null)
{
    <p>Filter String: @dataFilter.ToFilterString()</p>
    <p>OData String: @dataFilter.ToODataFilterString()</p>
}

@code {



    RadzenDataFilter<Demo> dataFilter;




    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        await base.OnAfterRenderAsync(firstRender);

        if (firstRender)
        {
            await EnumerableFilter();
        }
    }

    async Task EnumerableFilter()
    {
        await dataFilter.ClearFilters();
        await dataFilter.AddFilter(new CompositeFilterDescriptor()
            {
                Property = nameof(Demo.DemoValue),
                FilterValue = new int[] { 2 },
                FilterOperator = FilterOperator.Contains
            });
        StateHasChanged();
    }

    async Task TextFilter()
    {
        await dataFilter.ClearFilters();
        await dataFilter.AddFilter(new CompositeFilterDescriptor()
            {
                Property = nameof(Demo.Title),
                FilterValue = "t",
                FilterOperator = FilterOperator.Contains
            });
        StateHasChanged();
    }

    async Task MixedFilter()
    {
        await dataFilter.ClearFilters();
        await dataFilter.AddFilter(new CompositeFilterDescriptor()
            {
                Property = nameof(Demo.DemoValue),
                FilterValue = new int[] { 2 },
                FilterOperator = FilterOperator.Contains
            });
        await dataFilter.AddFilter(new CompositeFilterDescriptor()
            {
                Property = nameof(Demo.Title),
                FilterValue = "t",
                FilterOperator = FilterOperator.Contains
            });

        StateHasChanged();
    }

    public class Demo
    {
        public string Title { get; set; }
        public int DemoValue { get; set; }
    }

    


}

Thanks for the report! It will be fixed immediately!