CXone Studio handover to Cognigy failing with 500 error

We’re trying to set up a voicebot handover in CXone Studio for our Central time zone support queue. The goal is to let the NICE Cognigy bot handle initial intent classification before routing to a live agent.

I’m using the Session Handover action with the endpoint https://api.cognigy.ai/v1/sessions/handover. The request returns a 500 Internal Server Error immediately.

Here’s the snippet config:

{
 "sessionId": "{{conversation.sessionId}}",
 "botName": "SupportBot"
}

The logs show the payload is being sent correctly. Not sure why the server is rejecting it. Any ideas on what’s causing the 500?