How can a fax "to" be null?

We are processing a lot of fax messages from the RingCentral api. Recently, we discovered a lot of the records in the fax log api have no recipient. For example:

{
  "uri" : "https://platform.ringcentral.com/restapi/v1.0/account/2793220020/extension/2793222020/message-store?messageType=Fax&availability=Alive&dateFrom=2019-12-02T07:19:11.000Z&dateTo=2019-12-02T23:59:59.000Z&page=1&perPage=100",
  "records" : [ {
    "uri" : "https://platform.ringcentral.com/restapi/v1.0/account/2793220020/extension/2793222020/message-store/1098879326020",
    "id" : 1098879326020,
    "from" : {
      "phoneNumber" : "+17323901763",
      "location" : "South River, NJ"
    },
    "type" : "Fax",
    "creationTime" : "2019-12-02T18:00:40.000Z",
    "readStatus" : "Unread",
    "priority" : "Normal",
    "attachments" : [ {
      "id" : 1098879326020,
      "uri" : "https://media.ringcentral.com/restapi/v1.0/account/2793220020/extension/2793222020/message-store/1098879326020/content/1098879326020",
      "type" : "RenderedDocument",
      "contentType" : "application/pdf"
    } ],
    "direction" : "Inbound",
    "availability" : "Alive",
    "subject" : "+19089410855",
    "messageStatus" : "Received",
    "faxResolution" : "High",
    "faxPageCount" : 1,
    "lastModifiedTime" : "2019-12-02T18:00:40.769Z"
  }, {
    "uri" : "https://platform.ringcentral.com/restapi/v1.0/account/2793220020/extension/2793222020/message-store/1098877522020",
    "id" : 1098877522020,
    "from" : {
      "phoneNumber" : "+17323900896",
      "location" : "South River, NJ"
    },
    "type" : "Fax",
    "creationTime" : "2019-12-02T17:49:41.000Z",
    "readStatus" : "Unread",
    "priority" : "Normal",
    "attachments" : [ {
      "id" : 1098877522020,
      "uri" : "https://media.ringcentral.com/restapi/v1.0/account/2793220020/extension/2793222020/message-store/1098877522020/content/1098877522020",
      "type" : "RenderedDocument",
      "contentType" : "application/pdf"
    } ],
    "direction" : "Inbound",
    "availability" : "Alive",
    "subject" : "+19083157235",
    "messageStatus" : "Received",
    "faxResolution" : "High",
    "faxPageCount" : 1,
    "lastModifiedTime" : "2019-12-02T17:49:41.658Z"
  } ],
  "paging" : {
    "page" : 1,
    "totalPages" : 1,
    "perPage" : 100,
    "totalElements" : 2,
    "pageStart" : 0,
    "pageEnd" : 1
  },
  "navigation" : {
    "firstPage" : {
      "uri" : "https://platform.ringcentral.com/restapi/v1.0/account/2793220020/extension/2793222020/message-store?messageType=Fax&availability=Alive&dateFrom=2019-12-02T07:19:11.000Z&dateTo=2019-12-02T23:59:59.000Z&page=1&perPage=100"
    },
    "lastPage" : {
      "uri" : "https://platform.ringcentral.com/restapi/v1.0/account/2793220020/extension/2793222020/message-store?messageType=Fax&availability=Alive&dateFrom=2019-12-02T07:19:11.000Z&dateTo=2019-12-02T23:59:59.000Z&page=1&perPage=100"
    }
  }
}

As you can see, the "to" field is completely missing. How is this possible? The status shows that the message was sent successfully. But according to this, it went nowhere! Is this a bug? We've seen a lot of these lately. We are attempting to assign these messages to a user extension, but we have no data to show what extension it was sent to.

Further, the subject field contains a phone number. I find that very odd as well.