CRM Web API, Batch delete is not working

Batch post and patch are working well, but the batch delete is not working, I don't know what's the problem. Below is the request body and response content.

------------------------Request body

--batch_cd167ad9-868a-4a10-afe7-c1eb8cc80c94
Content-Type: multipart/mixed;boundary=changeset_d243a4fe-f9b6-4e58-9b96-a1782c874a19

--changeset_d243a4fe-f9b6-4e58-9b96-a1782c874a19
Content-Type: application/http
Content-Transfer-Encoding:binary
Content-ID: 1

DELETE apiurl/entity(db7a0de6-ceb2-e611-80e6-3863bb2e1360) HTTP/1.1
Content-Type: application/json;type=entry
--changeset_d243a4fe-f9b6-4e58-9b96-a1782c874a19
Content-Type: application/http
Content-Transfer-Encoding:binary
Content-ID: 2

DELETE apiurl/entity(dc7a0de6-ceb2-e611-80e6-3863bb2e1360) HTTP/1.1
Content-Type: application/json;type=entry
--changeset_d243a4fe-f9b6-4e58-9b96-a1782c874a19--
--batch_cd167ad9-868a-4a10-afe7-c1eb8cc80c94--

------------------------Response content

{"Message":"The message header '--changeset_d243a4fe-f9b6-4e58-9b96-a1782c874a19' is invalid. The header value must be of the format '<header name>: <header value>'.","ExceptionMessage":"The message header '--changeset_d243a4fe-f9b6-4e58-9b96-a1782c874a19' is invalid. The header value must be of the format '<header name>: <header value>'.","ExceptionType":"Microsoft.OData.Core.ODataException","StackTrace":" at Microsoft.OData.Core.ODataBatchReaderStream.ValidateHeaderLine(String headerLine, String& headerName, String& headerValue)\r\n at Microsoft.OData.Core.ODataBatchReaderStream.ReadHeaders()\r\n at Microsoft.OData.Core.ODataBatchReader.CreateOperationRequestMessageImplementation()\r\n at Microsoft.OData.Core.ODataBatchReader.InterceptException[T](Func`1 action)\r\n at System.Web.OData.Batch.ODataBatchReaderExtensions.<ReadOperationInternalAsync>d__9.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at System.Web.OData.Batch.ODataBatchReaderExtensions.<ReadChangeSetRequestAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at System.Web.OData.Batch.DefaultODataBatchHandler.<ParseBatchRequestsAsync>d__10.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at System.Web.OData.Batch.DefaultODataBatchHandler.<ProcessBatchAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at System.Web.Http.Batch.HttpBatchHandler.<SendAsync>d__0.MoveNext()","ErrorCode":400}