DynamoDB UPDATE_SKIP_NULL_ATTRIBUTES does not Apply to Complex Nested Properties

Question

I would like to update a single field in a nested property in DynamoDB. I figured using the UPDATE_SKIP_NULL_ATTRIBUTES SaveConfiguration would allow me to do this, but that appears to not be the case.

My DynamoDBTable:

@Getter
@Setter
@DynamoDBTable(tableName = "users")
public class User {
    @DynamoDBHashKey(attributeName = "Id")
    @DynamoDBAutoGeneratedKey
    private String id;

    @DynamoDBAtribute
    private String phone;

    @DynamoDBAtribute
    @DynamoDBTypeConvertedJson(targetType = Name.class)
    private Name name;

    @Getter
    @Setter
    @DynamoDBDocument
    public static class Name {
        @DynamoDBAttribute
        private String first;

        @DynamoDBAttribute
        private String last;
    }
}

I have a DynamoDBMapperConfig initialized like so:

private final DynamoDBMapperConfig config = DynamoDBMapperConfig.builder().withSaveBheavior(DynamoDBMapperConfig.SaveBehavior.UPDATE_SKIP_NULL_ATTRIBUTES).build();

And to save the record, I call the following:

mapper.save(user, config);

where mapper is a DynamoDBMapper and user is a User shown above.

The issue is that despite using the UPDATE_SKIP_NULL_ATTRIBUTES configuration, if user.name.last is null, the DB record's last field gets updated to null as well instead of the field being ignored.

This issue does not occur for non-nested fields, such as phone - if phone is null, the record's current value does not get overwritten.

Is there a way to make UPDATE_SKIP_NULL_ATTRIBUTES apply to nested objects as well? I simply need a way to modify single fields in nested objects.