SSL connection in async execution

[kaiserbergin]

Description

When executing multiple client calls via Task.WhenAll with the message The SSL connection could not be established, see inner exception., but the inner exception is null. Retry policies are a workaround at this point, but I'd like to understand the issue better, and understand what the inner exception should / could be.

Error Message: The SSL connection could not be established, see inner exception.
Inner Exception: null
Stack Trace:

   at Recurly.BaseClient.HandleResponse(IRestResponse resp)
   at Recurly.BaseClient.<>c__DisplayClass18_0`1.<MakeRequestAsync>b__0(Task`1 t)
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
   at Recurly.BaseClient.MakeRequestAsync[T](Method method, String url, Request body, Dictionary`2 queryParams, RequestOptions options, CancellationToken cancellationToken)

To Reproduce

Roughly what I'm doing, sans the resiliency policies, exception handling, and application logic:

var client = new Client(apiKey);
var @params = new ListInvoiceCouponRedemptionsParams
        {
            Sort = TimestampSort.UpdatedAt,
            BeginTime =  DateTimeOffset.Now.AddDays(-1),
            EndTime =  DateTimeOffset.Now,
        };

// Doing fifty invoice id's at a time from a larger batch
foreach (var taskChunk in idChunk.Chunk(50))
{
    var tasks = taskChunk.Select(async id =>
    {
        // Tried with newing up client or reusing, same issue applies...
        Pager<CouponRedemption> pager = client.ListInvoiceCouponRedemptions(id, @params);
        
        while (pager.HasMore)
        {
           // error happens here
           await pager.FetchNextPageAsync(cancellationToken).ConfigureAwait(false);
        }    
    });
    
    await Task.WhenAll(tasks);
}

Expected behavior

• Inner exception should not be null if specified in exception.
• If this is a my fault thing, I should change my code to look like... XXXX...
• If this is unexpected for the client, it should establish the SSL connection

Your Environment

• Library version: 4.51.0
• .NET version: 7.0