The webhook `MessageId` does not correspond to the actual event type

General
1

Consider the following webhook JSON, where MessageId is related to the event type. In this example, the source is a user-defined event.

How can I retrieve the corresponding event type using MessageId?

I have tried using /eventTypeGroups, but there is no matching ID. What is also confusing is that the Communication Restored event has a MessageId that matches an event type, while the Communication Error event does not.

{
   "Event": {
       "EventHeader": {
           "ID": "2388f93d-5cb0-48e0-9524-d8bb981e1629",
           "Timestamp": "2022-11-26T15:59:39.2988877Z",
           "Type": "System Event",
           "Version": "1.0",
           "Priority": 1,
           "PriorityName": "High",
           "Name": "External Event",
           "Message": "External Event",
           "Source": {
               "Name": "Event High",
               "FQID": {
                   "ServerId": {
                       "Type": "XPCO",
                       "Hostname": "ec2amaz-111k11j",
                       "Port": 80,
                       "Id": "2f04e7ee-2ee2-49d4-8415-de28dba7ef2e",
                       "Scheme": "http"
                   },
                   "ParentId": "2f04e7ee-2ee2-49d4-8415-de28dba7ef2e",
                   "ObjectId": "13860010-ded3-42ff-a2a9-cc6ba4a49636",
                   "FolderType": 0,
                   "Kind": "c9bdac3f-41dc-4afa-b057-61767a3914b7"
                }
           },
           "MessageId": "0fcb1955-0e80-4fd4-a78a-db47ee89700c"
       }
   },
   "Site": {
       "ServerHostname": "ec2amaz-111k11j",
       "AbsoluteUri": "http://ec2amaz-111k22j/",
       "ServerType": "XPCO"
   }
}