title: Durable Function SubOrchestrator does not return
body: <p>I have a durable function that defers to sub orchestrators, something like this:</p>
  
  <pre><code>[FunctionName("Trigger")]
  public static async Task OrchestrationFunctionFromHttpAsync(
      [OrchestrationTrigger]DurableOrchestrationContext context,
      ILogger log)
  {
      var firstResult = await context.CallSubOrchestratorAsync&lt;int&gt;("FirstFunction", null);
      var secondResult = await context.CallSubOrchestratorAsync&lt;int&gt;("SecondFunction", null);
  }
  </code></pre>
  
  <p>The first sub-orchestrator completes successfully, but the execution doesn't return to the orchestration function, so the second sub-orchestrator never gets called. How would I even investigate why this is happening?</p>