EventBridge duplicate events in Azure Function consumer

Need some help troubleshooting duplicate events arriving at my Azure Function. I am using the .NET SDK to register the webhook but receiving the same conversation:analyzed payload twice within milliseconds. The docs say:

“EventBridge delivers events with at-least-once semantics. You must implement idempotency in your consumer.”

Here is my handler. How do I filter these in C#?

public async Task<IActionResult> Run([EventGridTrigger] EventGridEvent eventGridEvent, ILogger log)
{
 if (eventGridEvent.EventType == "genesys.cloud.conversation.analyzed")
 {
 var data = JsonConvert.DeserializeObject<Conversation>(eventGridEvent.Data.ToString());
 // Process data
 }
 return new OkResult();
}