Error: 401 Unauthorized - Invalid Token Signature on token validation.
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?