Data Ingestion problem with free tire

I am ingesting 250 vectors. I do it in batches of 100. That is, 100, then 100, and then 50.

I know that I hit this code 3 times, but I see only 100 vectors when I login to the site…Sometimes I see some other numbers… Then I discover the some upsert calls throw exception: “Task has been canceled”…
Do I miss something here? Any ideas?

    public async void IngestVectors(IndexClient<RestTransport> idx, List<ISegment> segList, string indexNamespace = null)
        using (Log.VerboseCall())
            if (idx == null)
                throw new ArgumentNullException(nameof(idx));

            if (idx.Index.Status.IsReady == false)
                throw new Exception("Index is not in Ready state");

            if (segList == null || segList.Count == 0)
                throw new ArgumentException("Vector list is null or empty");

                mIndex = idx;
                List<Vector> vectors = new List<Vector>();

                for (int i = 0; i < segList.Count; i++)
                    if (segList[i] == null || String.IsNullOrWhiteSpace(segList[i].SegmentText))

                    Vector vec = new Vector()
                        Id = i.ToString(),
                        Values = segList[i].TextVector,
                        Metadata = new MetadataMap()

                    vec.Metadata.Add("segmentId", segList[i].segmentId);
                    vec.Metadata.Add("SegmentText", segList[i].SegmentText);

                    if (!String.IsNullOrEmpty(segList[i].Source.Trim()))
                        vec.Metadata.Add("Source", segList[i].Source);

                    if (segList[i].SrcType >= 0)
                        vec.Metadata.Add("SrcType", segList[i].SrcType.ToString());

                    vec.Metadata.Add("End", segList[i].TimeIngested.ToString("yyyy/MM/dd HH:mm:ss"));


                await mIndex.Upsert(vectors, indexNamespace);

                Log.VerboseFormat("Successfully ingested {0} vectors into Index: {1}", vectors.Count, mIndex.Index.Details.Name);
            catch (Exception ex)