Architect flow deployment failing with 422 on speech config

Architect & Flows
1

looking for advice on architect flow deployment. terraform apply fails with 422 unprocessable entity on genesyscloud_flow_ivr resource. env: au-1 byoc. provider: genesyscloud 2.5.1. the speech model ref seems valid but api rejects it. any ideas?

resource “genesyscloud_flow_ivr” “main” {
name = “ivr_main”
language = “en-AU”
settings {
speech_model_id = “${var.speech_model_id}”
}
}