Predictive Routing 429s during JMeter load test spike

Having some issues getting my configuration to work when pushing volume through the predictive routing API.

I am using JMeter with a Constant Throughput Timer set to 200 req/min against /api/v2/predictiverouting/outboundcampaigns. The script runs fine for the first 50 requests, then starts returning 429 Too Many Requests.

HTTP/1.1 429 Too Many Requests
Retry-After: 120

Is there a hidden cap on campaign start requests per minute? I am using Genesys Cloud SDK v2.15. Any help is appreciated.