External task Json object variable

Hi, I have an external task where I want to put a Json object as variable. However, when a client fetches this task, the Json variable is escaped. In my usecase, the client (no Java) is unable to parse the escaped Json. Is there a way to add a Json Object as variable to an external task without having it escaped on fetching?

Example fetch and lock
{
“activityId”: “externalGroupInvoice”,
“activityInstanceId”: “externalGroupInvoice:428623a5-cfdd-11e9-b814-2ab4d0752673”,
“errorMessage”: null,
“errorDetails”: null,
“executionId”: “428623a4-cfdd-11e9-b814-2ab4d0752673”,
“id”: “42870e06-cfdd-11e9-b814-2ab4d0752673”,
“lockExpirationTime”: “2019-09-10T13:03:03.224+0000”,
“processDefinitionId”: “Process_1:2:624848fc-ce5f-11e9-920d-0eaa66643623”,
“processDefinitionKey”: “Process_1”,
“processInstanceId”: “426a372f-cfdd-11e9-b814-2ab4d0752673”,
“retries”: null,
“suspended”: false,
“workerId”: “testWorker1223”,
“topicName”: “groupInvoices”,
“tenantId”: null,
“variables”: {
“groupedInvoices”: {
“type”: “Object”,
“value”: "[{"invoiceId":"2c9180836b371d79016b411f8ead06c7","invoiceGroupId":"30c0fd8f-10e1-4819-8d80-bfde23d9e335","status":"GROUPING","invoiceNumber":18800430,"sequenceNumber":3,"invoiceCode":"12","exactInvoiceId":null,"main":false},{"invoiceId":"2c9180826b371d18016b40a25d370304","invoiceGroupId":"30c0fd8f-10e1-4819-8d80-bfde23d9e335","status":"PROCESSED","invoiceNumber":18800400,"sequenceNumber":4,"invoiceCode":"12","exactInvoiceId":null,"main":true}]",
“valueInfo”: {
“objectTypeName”: “RawJSON”,
“serializationDataFormat”: “application/json”
}
}