Timeout calling long running AWS Lambda aspnetcore

Question

I have a long running lambda (sometimes 10+ minutes) and I call it in this manner

 using (var lambdaClient = new AmazonLambdaClient(AWSOptions.Credentials(),new AmazonLambdaConfig
            {
                 Timeout = TimeSpan.FromSeconds(1000)
            }))
            {                  

                InvokeRequest invoke = new InvokeRequest()
                {
                    FunctionName = functionName,
                    InvocationType = InvocationType.RequestResponse,
                    Payload = JsonConvert.SerializeObject(payload)
                };


                var invokeResponse = await lambdaClient.InvokeAsync(invoke);
                if (invokeResponse == null)
                    return null;

                using (var sr = new StreamReader(invokeResponse.Payload))
                {
                    return new TriggerLambdaResponse()
                    {
                        StatusCode = invokeResponse.HttpStatusCode,
                        Payload = await sr.ReadToEndAsync()
                    };
                }
            }

and I get exceptions from the InvokeAsync line after less than 1000 seconds (or 15 minutes)

Exception:{ ClassName:System.Threading.Tasks.TaskCanceledException Message:The operation was canceled. Data:null InnerException:{ ClassName:System.IO.IOException Message:Unable to read data from the transport connection: Operation canceled. Data:null InnerException:{ ClassName:System.Net.Sockets.SocketException Message:Operation canceled

From what I understand the lambda still continues its function while the calling code is timing out. I am running on docker aspnetcore 2.2 in linux. Is there any other defaulted timeout I should set? I can see the AWS sdk is using the httpconnection class but I don't have access to its parameters. Any ideas?