CXone Studio Session Handover to Genesys Cloud failing with 400

Trying to handover a voice session from NICE Cognigy in CXone Studio to our Genesys Cloud queue. The Studio flow hits the Transfer block but drops straight to the error path.

  • CXone Studio v2.1
  • Genesys Cloud API v2
  • Using GetRESTProxy to call /api/v2/conversations/voice
  • Payload includes from, to, and routing objects

The response is a 400 Bad Request with {"errors":[{"code":"invalid","message":"Invalid routing data"}]}. I’ve checked the routing file ID and it’s valid. Here’s the JSON I’m sending to the transfer endpoint: