If you're noticing high DataPlane cores utilization after upgrading sonicOS version to 184.108.40.206-89n, latency in LAN network and firewall GUI management please consider the resolution provided in this article.
NOTE:This is in fact that there were no changes in the environment, topology and traffic profile when observing this issue post firmware update. Also, perform safe downgrade to the version you were previously on and check if it takes the CPU utilization back to normal which is a strong indication the issue is related to this hotfix. How Do I Safely Perform A Firewall Firmware Downgrade?
We have a hotfix release to address this issue hence please upgrade the firewall to 220.127.116.11-89n--HFGEN6-2737-17n by following below steps: