Outbound Campaign API 429 Too Many Requests during JMeter spike test

So I’m seeing a very odd bug with the Genesys Cloud Outbound Campaign API (/api/v2/outbound/campaigns) when hitting it with 50 concurrent threads from our Singapore staging environment using JMeter 5.6.2. The load test consistently triggers 429 Too Many Requests after just 10 seconds, even though the documented rate limit should allow for higher throughput. Is there a specific header or pacing strategy I’m missing to avoid this immediate throttling?