JWT Token Validation Fails During High-Concurrent JMeter Load

Error: 401 Unauthorized - Invalid Token Signature on /api/v2/architect/flows.

Running JMeter 5.4 with 200 concurrent threads against Genesys Cloud US1. Token generation works fine at low volume, but fails when throughput exceeds 50 req/sec. Suspect rate limiting or clock skew in token validation service. Using standard OAuth client credentials flow. Is there a specific header or payload size limit causing signature mismatch under load?