This test/_api/web/lists/GetByTitle(‘doclib1’)/items?$ select=ID,DocIcon,LinkFilename,Modified,Editor/Title,UniqueId,GUID&$ expand=Editor returns me

    {   "d": {     "results": [       {         "__metadata": {           "id": "b9c377f3-79cc-466a-b495-5834cff90ce0",           "uri": "https://quantr.sharepoint.com/test/_api/Web/Lists(guid\u00275d9df756-8067-4599-b1cc-fc9ca610c4fe\u0027)/Items(1)",           "etag": "\"1\"",           "type": "SP.Data.Doclib1Item"         },         "Editor": {           "__metadata": {             "id": "7980221b-5cff-4d10-8350-fed6b6f93894",             "type": "SP.Data.UserInfoItem"           },           "Title": "wordpress"         },         "Id": 1,         "ID": 1,         "Modified": "2017-12-12T17:08:46Z",         "UniqueId": "84ea42c1-abb4-466c-a7b4-532fbaf1515a",         "LinkFilename": "大圍 !",         "GUID": "f01e761d-0fd4-4d7d-a447-e3bd609bc821"       },     } } 

But this test/_api/web/lists/GetByTitle(‘doclib1’)/items?$ select=ID,DocIcon,LinkFilename,Modified,Editor/Title,UniqueId,GUID&$ expand=Editor&$ filter=UniqueId+eq+guid%2784ea42c1-abb4-466c-a7b4-532fbaf1515a%27 returns me empty json.

{   "d": {     "results": []   } } 

If i filter by the GUID, it works again. Is it a bug? UniqueId is unable to be filter?

thanks