Why does this setting block concurrent OAuth requests?

  • Genesys Cloud BYOC Edge 24.2
  • Region: Asia/Pacific Southeast
  • Tool: JMeter 5.6.2
  • Test: 100 concurrent threads hitting POST /api/v2/oauth/token

Why does this setting trigger immediate 403 Forbidden responses instead of standard 429 rate limits? The logs show invalid_grant mixed with access_denied when concurrency spikes. Is there a specific security policy or IP reputation check kicking in at this volume? Need to validate token refresh throughput for softphone load tests.