Missing data after uploading CSV to s3 (Kotlin)

Question

after copying table into csv file, i uploaded csv file to s3 (batch).

i checked csv file has 100 rows, but when is uploaded on s3, it has 95 rows.

missing number is random like 30->26 , 7420590 -> 7420566 , 7730590 -> 7730577.

it seems like the size of file doesn't matter

what is wrong with this?

 override fun run(baseDate: String) {
        val sqlSession: SqlSession = datastoreSqlSessionFactory.openSession(ExecutorType.BATCH, true)
        val con = sqlSession.connection
        val copyManager = CopyManager(con.unwrap(BaseConnection::class.java))
        val file = File("./buildings.csv")
        val stream: OutputStream = BufferedOutputStream(FileOutputStream(file.absolutePath))
        val bucketName = "manage-batch-dev"
        val key = "/data"

        val copySql = String.format(
            "copy buildings_table to stdout"
        )

        try {
            copyManager.copyOut(copySql, stream)
            s3.upload(bucketName, key, file.absolutePath)

        } catch (e: Exception) {
            log.error("BuildingsOutlinesSummariesCopyOutBatch Error:${e.message}", e)
            throw e
        } finally {
            stream.close()
            sqlSession.close()
           
        }

        file.delete()
    }

and s3.upload

 @Throws(IOException::class, AmazonServiceException::class)
    fun upload(bucketName: String, key: String, filePath: String): PutObjectResult {
        try {
            
            val request = PutObjectRequest(bucketName, key, File(filePath))
            val result = client.putObject(request)

            return result
        } catch (e: AmazonServiceException) {
            throw e
        } catch (e: java.lang.Exception) {
            throw e
        }
    }