Data is not returned for certain RICS - Identifier Validation Error in Intraday Summaries Extraction

I'm trying to extract tick data by posting the below Extraction Request. Everything works fine, except for the RIC identifier KOAH8 which fails with the following error in the body of the response. I've also set AllowHistoricalInstruments to true in the ValidationOptions in InstrumentIdentifierList as seen in the request.

Error:

"IdentifierValidationErrors":[{"Identifier":{"@odata.type":"#ThomsonReuters.Dss.Api.Content.InstrumentIdentifier","Identifier":"KOAH8","IdentifierType":"Ric","Source":""},"Message":"Not found"}]}

I'm not sure what this error means and why no data is being returned for it. Any help regarding this would be greatly appreciated. Thanks!

Extraction Request:

{
   "ExtractionRequest" : {
      "@odata.type" : "#ThomsonReuters.Dss.Api.Extractions.ExtractionRequests.TickHistoryIntradaySummariesExtractionRequest",
      "ContentFieldNames" : [
         "Close Ask",
         "Close Bid",
         "High",
         "High Ask",
         "High Bid",
         "Last",
         "Low",
         "Low Ask",
         "Low Bid",
         "No. Asks",
         "No. Bids",
         "No. Trades",
         "Open",
         "Open Ask",
         "Open Bid",
         "Volume"
      ],
      "IdentifierList" : {
         "@odata.type" : "#ThomsonReuters.Dss.Api.Extractions.ExtractionRequests.InstrumentIdentifierList",
         "InstrumentIdentifiers" : [
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FBTSZ7"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FGBSZ7"
            },
            {
               "Identifier" : "FBTPZ7",
               "IdentifierType" : "Ric"
            },
            {
               "Identifier" : "FBONZ7",
               "IdentifierType" : "Ric"
            },
            {
               "Identifier" : "FOATZ7",
               "IdentifierType" : "Ric"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FGBMZ7"
            },
            {
               "Identifier" : "FGBLZ7",
               "IdentifierType" : "Ric"
            },
            {
               "Identifier" : "FGBXZ7",
               "IdentifierType" : "Ric"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FLGZ7"
            },
            {
               "Identifier" : "TYZ7",
               "IdentifierType" : "Ric"
            },
            {
               "Identifier" : "USZ7",
               "IdentifierType" : "Ric"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "AULZ7"
            },
            {
               "Identifier" : "FVZ7",
               "IdentifierType" : "Ric"
            },
            {
               "Identifier" : "TUZ7",
               "IdentifierType" : "Ric"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FBTSH8"
            },
            {
               "Identifier" : "FGBSH8",
               "IdentifierType" : "Ric"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FBTPH8"
            },
            {
               "Identifier" : "KOAH8",
               "IdentifierType" : "Ric"
            },
            {
               "Identifier" : "FOATH8",
               "IdentifierType" : "Ric"
            },
            {
               "Identifier" : "FGBMH8",
               "IdentifierType" : "Ric"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FGBLH8"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FGBXH8"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FLGH8"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "TYH8"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "USH8"
            },
            {
               "Identifier" : "AULH8",
               "IdentifierType" : "Ric"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "FVH8"
            },
            {
               "IdentifierType" : "Ric",
               "Identifier" : "TUH8"
            }
         ],
         "ValidationOptions" : {
            "AllowHistoricalInstruments" : 1
         },
         "UseUserPreferencesForValidationOptions" : 0
      },
      "Condition" : {
         "MessageTimeStampIn" : "LocalExchangeTime",
         "ReportDateRangeType" : "Range",
         "QueryStartDate" : "2017-10-20T00:00:00Z",
         "QueryEndDate" : "2017-10-21T00:00:00Z",
         "SummaryInterval" : "OneMinute",
         "TimebarPersistence" : 1,
         "DisplaySourceRIC" : 1
      }
   }
}