httpclientfactory-blazor.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddHttpClient();
    services.AddSingleton<CosmosClient>(serviceProvider =>
    {
        IHttpClientFactory httpClientFactory = serviceProvider.GetRequiredService<IHttpClientFactory>();

        CosmosClientOptions cosmosClientOptions = new CosmosClientOptions()
        {
            HttpClientFactory = httpClientFactory.CreateClient,
            ConnectionMode = ConnectionMode.Gateway
        };


        return new CosmosClient("<connection-string>", cosmosClientOptions);
    });

    //... other service registration
}

@ylr-research

My code example has services.AddHttpClient();, how are you registering the IHttpClientFactory?

You are just creating a Transient instance of HttpClient, which that by itself is incorrect, you should avoid creating new HttpClients all the time.

@ealsur I fixed those lines already an the error is still the same.