The CA API Gateway can apply rate limits to inbound requests based upon certain conditions such as requestor IP addresses, requested SOAP operations, or other custom conditions. There is an internal process that flushes rate limiters on a periodic basis. This rate limiter may flush some blacked out limits if a certain condition is met. Specifically: If the "Blackout" setting is configured with a value that would exceed 13613 milliseconds then the Gateway will need to be reconfigured to accommodate this setting and avoid preemptively flushing any applicable limits.
If there are policies with an Apply Rate Limit assertion then verify whether the "Blackout" checkbox is enabled and if the blackout time is a value exceeding 13 seconds. If any assertions have a value exceeding 13 seconds then please refer to the Resolution section of this article for subsequent configuration procedures