title: .NET Core MVC SignalR hub methods not running concurrently
body: <p>I am having an issue with the latest version of SignalR in .NET Core 3.1.  It seems that one of my hub methods are blocking a second hub method.</p>
  <p>The hub methods are called correctly on the client side.  There is no delay after the call to GetPriceHistoryDifferentialAsync, which is a LINQ query on the server, before also logging that the second GetPriceHistoryAsync, which is a quick button click, was called.</p>
  <p><strong>client console log</strong></p>
  <blockquote>
  <p>invoke: GetPriceHistoryAsync<br>
  invoke: GetPriceHistoryDifferentialAsync<br>
  invoke: GetPriceHistoryAsync</p>
  </blockquote>
  <p>Next is the debug output in Visual Studio on the client side.</p>
  <p><strong>server log</strong></p>
  <blockquote>
  <p>Stocks.Web.Hubs.StocksHub: Information: GetPriceHistoryAsync A UKhqAp6VQheTCrxYWeyjbQ<br>
  Stocks.Web.Hubs.StocksHub: Information: GetPriceHistoryDifferentialAsync UKhqAp6VQheTCrxYWeyjbQ<br></p>
  </blockquote>
  <p>There is a delay until GetPriceHistoryDifferential completes and then any remaining calls to GetPriceHistory complete.</p>
  <blockquote>
  <p>Stocks.Web.Hubs.StocksHub: Information: GetPriceHistoryAsync AAN UKhqAp6VQheTCrxYWeyjbQ<br></p>
  </blockquote>
  <p>There was previously no delay in returning data with the button click GetPriceHistory method calls while the GetPriceHistoryDifferential query method call was running.  I think updating to .NET Core 3.1 and the latest SignalR is when this issue began.
  Does anyone know what caused this problem or how to make SignalR hub methods run concurrently again?  I am using the async/await model, and both hub methods await Clients.Caller.SendCoreAsync.</p>