Data Action Timeout During High Load

Can anyone clarify the correct configuration for ensuring data actions remain responsive during high-concurrency load tests? We are running JMeter 5.6 and seeing timeouts.

  1. Architect flow triggers Data Action.
  2. Payload sent to external API.
  3. Timeout occurs at 500 concurrent sessions.

Error code 504 appears in logs. Is this a rate limit or a configuration issue?