SASL authentication failure prevents cluster communication

SASL authentication fails when Control Center, brokers, or Telemetry Reporter attempt to communicate, causing service startup or runtime failures.

Verify security configuration matches across all brokers, Telemetry Reporter, and Control Center (SASL_SSL, SASL_PLAINTEXT, SSL). Verify correct JAAS configuration was detected. Check ACLs if enabled. Test with console-producer/consumer using same security settings.