API PID Request "Too Many Requests" Error

Hi,

I am running a weekly process in MS .net to “unset” some custom properties. I first run a call using the code below to retrieve the PID to use in the unset call.   It fails to retrieve the PID in about 20% of the calls returning the error message “To Many Requests”.  The failures are not sequential and the volume is not high.  The last time it ran there were 45 calls to retrieve the PID and 9 of them failed with the “Too Many Requests” error message.  If I return the 9 (in this case) they are all successful.  Anyone know why this may be happening?  It runs at 2:30am EST every Monday.

John

s = "https://a.klaviyo.com/api/v2/people/search?api_key=pk_xxxxxxxxxxxxx&email=<EMAIL>";
                s = s.Replace("<EMAIL>", email);
                var client = new RestClient(s);
                var request = new RestRequest(Method.GET);
                request.AddHeader("Accept", "application/json");
                request.AddHeader("Content-Type", "application/json");
                var response = client.Execute(request);
                if (response.StatusCode != System.Net.HttpStatusCode.OK)
                {
                    msg = "PID failed to retrieve for email " + email;
                    writelog("E", 0, response, msg);
                }
                else
                {
                   
                    DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof(apiresponse));
                    MemoryStream stream = new MemoryStream(Encoding.UTF8.GetBytes(response.Content));
                    stream.Position = 0;
                    apiresponse responseDetail = (apiresponse)jsonSerializer.ReadObject(stream);
                    pid = responseDetail.id;
                    stream.Close();
                    {
                        msg = "PID, " + pid + " successfully retrieved for email " + email;
                        writelog("I", 0, null, msg);
                    }
                }