EventBridge rule not firing for conversation events — how to debug the event pattern?

Trying to get an EventBridge rule to fire when a Genesys Cloud conversation starts. The rule seems valid, but nothing triggers.

Here’s the pattern I’m using:

{
 "source": ["com.genesyscloud.events"],
 "detail-type": ["v2.conversations.conversation"],
 "detail": {
 "event_type": ["created"]
 }
}

I’ve verified the event is being sent to EventBridge by checking the console. The event payload looks like this:

{
 "event_type": "created",
 "conversation_id": "12345",
 "timestamp": "2023-10-27T10:30:00Z"
}

But the rule doesn’t match. Any ideas what’s wrong with the pattern?