I created ASP.NET Core MVC .NET 8 application. I added simple WebApi ProductController which returns Json list of products.
Then I added Blazor WebAssembly Standalone app to the solution and included one page from the Blazor app to my ASP.NET Core app. I want to implement rich UI for products with this Blazor component. To get data (products) I call the ProductController with RestSharp component. Then strange happens – the product list refreshed for a second and then disappear. If I try test data (simple mock with list of products) all works fine. I checked the ProductController WebApi it works fine, returns json data.
Please help to fix this.

Blazor component file:

@inject NavigationManager NavManager

<h3>Products</h3>

@if(_viewModel == null)
{
    <p><em>Loading...</em></p>
}
else
{
    <ul>
        @foreach (var product in _viewModel.Products)
        {
            <li>@product.Name</li>
        }
    </ul>
    @if(_viewModel.Products.Count == 0)
    {
        <p><em>No products found</em></p>
    }
}

@code {
    private ProductIndexViewModel _viewModel;
    private IDataProviderFactory _dataProviderFactory;
    private IProductDataProvider _productDataProvider;

    protected override async Task OnInitializedAsync()
    {
        _dataProviderFactory = GetDataProviderFactory();
        _productDataProvider = _dataProviderFactory.CreateProductDataProvider();                
        _viewModel = await _productDataProvider.GetByGroupAndPageAsync(0, 1, 5);
    }

    private IDataProviderFactory GetDataProviderFactory()
    {
        return new RestDataProviderFactory(NavManager.BaseUri);
        //return new TestDataProviderFactory();
    }
}

RestSharp call:

        public async Task<ProductIndexViewModel> GetByGroupAndPageAsync(int productGroupId, int pageNumber, int itemsPerPage)
        {            
            string uri = $"{GetApiUri()}/GetByGroupAndPage/{productGroupId}/{pageNumber}/{itemsPerPage}";
            var request = new RestRequest(uri, Method.Get);
            var restResponse = await restClient.ExecuteGetAsync<ProductIndexViewModel>(request);
            if (restResponse.IsSuccessful)
            {
                ProductIndexViewModel viewModel = restResponse.Data;
                return viewModel;
            }
            return new ProductIndexViewModel();
        }