Running into a weird bug with Predictive Routing API 429s in JMeter

So I’m seeing a very odd bug with the Genesys Cloud Predictive Routing API when scaling JMeter threads. The /api/v2/outbound/campaigns endpoint keeps throwing 429 errors after just 20 concurrent requests, despite the docs suggesting higher limits for enterprise tiers.

HTTP/1.1 429 Too Many Requests
Retry-After: 60

The test is running from the Singapore region using JMeter 5.6. Is there a specific header or config I need to adjust to handle higher throughput for campaign polling?