Csharp SignalR 与自定义 RetryPolicy 重新连接不遵守该策略并增加了额外的延迟

我在.NET 6上使用的是SignalR.NET客户端和服务器，重新连接延迟的工作方式似乎与我预期的有所不同.我在服务器上使用以下代码来定义自定义RetryPolicy:

connection = new HubConnectionBuilder()
  .WithUrl(url)
  .WithAutomaticReconnect(new RetryPolicy())
  .Build();

public class RetryPolicy : IRetryPolicy
{
  public TimeSpan? NextRetryDelay(RetryContext retryContext)
  {

    var delay = retryContext.PreviousRetryCount switch
    {
      < 5 => TimeSpan.FromSeconds(0),
      < 10 => TimeSpan.FromSeconds(5),
      _ => TimeSpan.FromSeconds(10),
    };
    Console.WriteLine($"NextRetryDelay count: {retryContext.PreviousRetryCount} elapsed: {retryContext.ElapsedTime} delay: {delay}");
    return delay;
  }
}

当我触发断开连接时，我得到以下输出:

NextRetryDelay count: 0 elapsed: 00:00:00 delay: 00:00:00
NextRetryDelay count: 1 elapsed: 00:00:08.1187903 delay: 00:00:00
NextRetryDelay count: 2 elapsed: 00:00:12.1619132 delay: 00:00:00
NextRetryDelay count: 3 elapsed: 00:00:16.2117377 delay: 00:00:00
NextRetryDelay count: 4 elapsed: 00:00:20.2883145 delay: 00:00:00
NextRetryDelay count: 5 elapsed: 00:00:24.3593463 delay: 00:00:05
NextRetryDelay count: 6 elapsed: 00:00:33.4387382 delay: 00:00:05
NextRetryDelay count: 7 elapsed: 00:00:42.4919265 delay: 00:00:05
NextRetryDelay count: 8 elapsed: 00:00:51.5778513 delay: 00:00:05
NextRetryDelay count: 9 elapsed: 00:01:00.6560698 delay: 00:00:05
NextRetryDelay count: 10 elapsed: 00:01:09.7329655 delay: 00:00:10
NextRetryDelay count: 11 elapsed: 00:01:23.7992479 delay: 00:00:10
NextRetryDelay count: 12 elapsed: 00:01:37.8539388 delay: 00:00:10

对于每个延迟，似乎都会有大约4秒的额外延迟，超出我在此自定义RetryPolicy中指定的时间.第二个延迟甚至还有额外的8秒，这些值看起来非常可重现，尽管不是完全可以重现.

我在这里调整了测试的实际值，但我的目标是在开始时进行几次非常快速的重试.这似乎是不可能的，因为这个从哪里冒出来的~8秒的初始延迟.

这些额外的延迟来自哪里，我如何让.NET尊重我在这里设置的RetryPolicy？