Dynamodb get query returns one of the entry fields null

I have this data class

    import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAttribute;
    import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBHashKey;
    import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBRangeKey;
    import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTable;
    
    @DynamoDBTable(tableName = "AtcDevDocumentImages")
    public class ImageDetail {
    
      @DynamoDBHashKey(attributeName = "DocumentId")
      private String documentId;
    
      @DynamoDBRangeKey(attributeName = "TrackPosition")
      private int trackPosition;
    
      @DynamoDBAttribute(attributeName = "ImageId")
      private String imageId;
    
      @DynamoDBAttribute(attributeName = "ImageUrl")
      private String imageUrl;
    
      @DynamoDBAttribute(attributeName = "ImageName")
      private String imageName;
    
      @DynamoDBAttribute(attributeName = "Width")
      private double width;
    
      @DynamoDBAttribute(attributeName = "Height")
      private double height;
    ...
    ...
    }

And this is the entry in my dynamodb table

This is my service class performing the query for documentId (get all images for document id x):

import com.amazonaws.client.builder.AwsClientBuilder;
    import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
    import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder;
    import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;
    import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapperConfig;
    import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBQueryExpression;
    import com.amazonaws.services.dynamodbv2.datamodeling.PaginatedQueryList;
    import java.text.SimpleDateFormat;
    import java.util.List;
    import java.util.TimeZone;
    import org.slf4j.Logger;
    
    public class ImageService {
    
      private AmazonDynamoDB amazonDynamoDB;
      private DynamoDBMapper mapper;
    
      private SimpleDateFormat sdf;
    
      private String tableName;
    
      public ImageService local() {
        amazonDynamoDB =
            AmazonDynamoDBClientBuilder.standard()
                .withEndpointConfiguration(
                    new AwsClientBuilder.EndpointConfiguration("http://localhost:8000", "local"))
                .build();
        mapper = new DynamoDBMapper(amazonDynamoDB);
        return this;
      }
    
      public ImageService cloud() {
        amazonDynamoDB = AmazonDynamoDBClientBuilder.standard().build();
        mapper = new DynamoDBMapper(amazonDynamoDB);
        this.tableName = System.getenv("IMAGES_TABLE");
        return this;
      }
    
      public ImageService init() {
        sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
        sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
        return this;
      }
    
      public List<ImageDetail> getImagesByDocumentId(String documentId, Logger logger) {
        DynamoDBMapperConfig mapperConfig =
            DynamoDBMapperConfig.builder()
                .withTableNameOverride(
                    DynamoDBMapperConfig.TableNameOverride.withTableNameReplacement(tableName))
                .build();
    
        ImageDetail imageDetailKey = new ImageDetail();
        imageDetailKey.setDocumentId(documentId); // Ensure this sets the documentId field
    
        DynamoDBQueryExpression<ImageDetail> queryExpression =
            new DynamoDBQueryExpression<ImageDetail>()
                .withHashKeyValues(imageDetailKey)
                .withConsistentRead(false);
    
        PaginatedQueryList<ImageDetail> query =
            mapper.query(ImageDetail.class, queryExpression, mapperConfig);
        logger.info("results: ");
        logger.info(query.toString());
        return query;
      }
    }

The result I get back is this: 1703153761850,"2023-12-21 10:16:01 da71511d-f14e-48d2-8f33-ae623818745d INFO XyzService - ImageDetail{documentId='a0d266bc-85ce-4595-a85d-fe1142c81fdf', id='null', trackPosition=6, imageUrl='null', name='image1.png', width=1920.0, height=938.0}

I am a bit at loss as to why imageId and imageUrl are null. Any suggestion or recommendation very much welcome. Thank you