Genesyscloud_architect_flow 400 - Invalid JSON Payload via Terraform

Architect & Flows
1

I’m trying to figure out why the architect_flow resource fails during apply when using custom data nodes. The provider version is 1.65.0 and Terraform is v1.9.8. The error is 400 Bad Request with message Invalid JSON payload. The flow definition works fine when imported via the UI or API directly.

Here is the HCL snippet causing the issue:

resource "genesyscloud_architect_flow" "test_flow" {
 name = "Test Flow"
 description = "Test"
 flow_version {
 ...
 }
}

Any hints on what might be wrong with the structure?