Predictive Routing Score 400 Bad Request on AU-1 BYOC

Trying to understand why predictive routing score creation fails with 400 Bad Request during terraform apply on AU-1 BYOC.

provider: 2.5.1
tf: 1.6.0
resource: genesyscloud_routing_predictor

error: “invalid predictor configuration: missing required field ‘model_type’”

hcl config looks valid. api docs say model_type is optional. any ideas?