How to create event by MS Graph with room as location?

I'm trying to create an event by MS Graph to Calendar with room that have been set in my outlook account. But the problem is that the room can't be booked without adding the room as attendees.

If I only add the room as location, the Calendar in the room account won't be notified and booked.

{
  "subject": "Let's go picnicking",
  "body": {
    "contentType": "HTML",
    "content": "Does late morning work for you?"
  },
  "start": {
      "dateTime": "2018-03-20T12:00:00",
      "timeZone": "Pacific Standard Time"
  },
  "end": {
      "dateTime": "2018-03-20T14:00:00",
      "timeZone": "Pacific Standard Time"
  },
  "location":{
      "coordinates": {"@odata.type": "microsoft.graph.outlookGeoCoordinates"},
      "displayName":"RM.Papaya",
      "locationType": "conferenceRoom",
      "address": {"@odata.type": "microsoft.graph.physicalAddress"}
  },
  "locations": [
        {
            "displayName": "RM.Papaya",
            "locationType": "conferenceRoom"
        }
    ],
  "attendees": [
    {
      "emailAddress": {
        "address":"Matthew_Liao@Ginaworks.onmicrosoft.com",
        "name": "Matthew Liao"
      },
      "type": "required"
    }
  ]
}

However, if I add the room also as location and attendees, the Calendar in the room account will be notified, but the display of location is only a text unconnected with the room account.

{
  "subject": "Let's go picnicking",
  "body": {
    "contentType": "HTML",
    "content": "Does late morning work for you?"
  },
  "start": {
      "dateTime": "2018-03-20T12:00:00",
      "timeZone": "Pacific Standard Time"
  },
  "end": {
      "dateTime": "2018-03-20T14:00:00",
      "timeZone": "Pacific Standard Time"
  },
  "location":{
      "displayName":"RM.Papaya",
      "locationType": "conferenceRoom",
      "address": {"@odata.type": "microsoft.graph.physicalAddress"}
  },
  "locations": [
        {
            "displayName": "RM.Papaya",
            "locationType": "conferenceRoom"
        }
    ],
  "attendees": [
    {
      "emailAddress": {
        "address":"Matthew_Liao@Ginaworks.onmicrosoft.com",
        "name": "Matthew Liao"
      },
      "type": "required"
    },
    {
      "emailAddress": {
        "address":"rm.papaya@Ginaworks.onmicrosoft.com",
        "name": "RM.Papaya"
      },
      "type": "required"
    }
  ]
}

Is that reasonable or logical? Or did I make any mistake in my code? Thanks for helping.

The display issue is a limitation of the API. This is something we hope to fix, but I can't hazard a guess when that might happen.