Get peak date time information from logs
cat qradar.log |grep SourceMonitor |grep ecs-ec-ingress |sed -r 's#^(.+?)::.+ Peak in the last 60s: (.+?)\. Max Seen.+#\1 \2#'
Go to QRadar UI and query that time period and group by EventID or SourceIP for detecting root cause of the problem.
If the traffic which causes the peaks is abnormal, if it is possible try to drop unnecessary traffic at the log source level by solving the root cause of the problem.