Outbound Campaign API 429 Errors during JMeter Load Simulation

Why does the Outbound Campaign API is rejecting requests during our initial load testing phase?

We are running JMeter 5.6 against the Genesys Cloud US1 environment to validate the throughput of our outbound dialing setup. The test simulates a ramp-up of 50 concurrent threads calling the /api/v2/outbound/campaigns endpoint to update campaign status.

After about 30 seconds, we start receiving HTTP 429 Too Many Requests errors. The response headers show Retry-After: 2. I have checked the standard API rate limits documentation, but it is not clear if outbound campaigns have a separate, stricter limit compared to standard architect flows.

The JMeter thread group is configured with a constant throughput timer. We are not hitting the WebSocket limits here, just standard REST calls. Is there a specific throttle for campaign updates that we need to account for in our capacity planning? The error logs do not provide much detail beyond the 429 code. We need to ensure our dialer can handle the burst traffic without dropping updates. Any insight on the expected limits for this endpoint would be appreciated.