$CONTEXT.workflowInstanceId not resolved as argument to Service call

{
  "name": "ansibleAction",
  "functionRef": {
    "refName": "triggerAnsibleManually",
    "arguments": {
      "jobId": 7,
      "workflowInstanceId": "$CONTEXT.workflowInstanceId"
    }
  }
} 

public void triggerJob(Integer jobId, String workflowInstanceId) {
    System.out.println("workflowInstanceId = " + workflowInstanceId);
    System.out.println("jobId = " + jobId);
}