Text Anchors don't work after a document has been added to a package

var signer1 = (Email: "[email protected]",
                           Id: "signer-1",
                           FirstName: "David",
                           LastName: "NormalGmail",
                           Company: "ABC Company",
                           Title: "Software Developer");

            var doc = (Name: "Testing Doc",
                       Id: "DocId1");

            var anchor = (Text: "Please Sign",
                          Occurrence: 0,
                          Character: 0,
                          Width: 200,
                          Height: 50);

            PackageId packageId = null;
            using (var fs = File.OpenRead(@"test.pdf"))
            {
                var package = PackageBuilder.NewPackageNamed(doc.Name + " Package")
                              .WithSettings(DocumentPackageSettingsBuilder.NewDocumentPackageSettings())
                              .WithSigner(SignerBuilder
                                          .NewSignerWithEmail(signer1.Email)
                                          .WithCustomId(signer1.Id)
                                          .WithFirstName(signer1.FirstName)
                                          .WithLastName(signer1.LastName)
                                          .WithCompany(signer1.Company)
                                          .WithTitle(signer1.Title))
                              .WithDocument(DocumentBuilder
                                            .NewDocumentNamed(doc.Name)
                                            .FromStream(fs, DocumentType.PDF)
                                            .WithId(doc.Id)
                                            // This signature is placed correctly according to the text anchor
                                            .WithSignature(SignatureBuilder.SignatureFor(signer1.Email)
                                                           .WithPositionAnchor(TextAnchorBuilder.NewTextAnchor(anchor.Text)
                                                                               .AtPosition(TextAnchorPosition.TOPLEFT)
                                                                               .WithOccurrence(anchor.Occurrence)
                                                                               .WithCharacter(anchor.Character)
                                                                               .WithOffset(0, -anchor.Height)
                                                                               .WithSize(anchor.Width, anchor.Height)))).Build();

                packageId = eslClient.CreatePackage(package);
            }

            // The text anchor here is completely ignored
            var sigBuilder = SignatureBuilder.SignatureFor(signer1.Email)
                             .WithPositionAnchor(TextAnchorBuilder.NewTextAnchor(anchor.Text)
                                                 .AtPosition(TextAnchorPosition.BOTTOMLEFT)
                                                 .WithOccurrence(anchor.Occurrence)
                                                 .WithCharacter(anchor.Character)
                                                 .WithOffset(0, 0)
                                                 .WithSize(anchor.Width, anchor.Height));

            var documentPackage = eslClient.GetPackage(packageId);
            eslClient.ApprovalService.AddApproval(documentPackage, doc.Id, sigBuilder.Build());