WFM Bulk Schedule Import Failing with 422 Unprocessable Entity in ap-southeast-1

I’ve spent hours trying to figure out why the WFM schedule bulk import is failing intermittently. Using the genesyscloud_wfm_user_schedule resource in Terraform v1.7.5 with provider v1.12.0. The deployment pipeline runs via GitHub Actions in Sydney. Error returned is 422 Unprocessable Entity.

Payload structure matches documentation. Issue appears only when shifting patterns across timezone boundaries (AEST to UTC). No validation errors on individual schedule objects before the bulk call.

resource "genesyscloud_wfm_user_schedule" "shift_pattern" {
 external_id = "shift_pattern_001"
 name = "Night Shift AU"
 schedule_type = "fixed"
 
 schedule_data {
 start_time = "2023-10-01T08:00:00+11:00"
 end_time = "2023-10-01T16:00:00+11:00"
 shift_type = "work"
 }
}

API response body contains: "message": "Invalid schedule data format". This is misleading as the ISO 8601 timestamps are correct. Does the provider handle timezone offset conversion incorrectly during the POST request to /api/v2/wfm/schedules? Need to verify if manual API calls via Postman succeed with identical payload.