High CPU can be due to many factors. It is your production system. You should do more analysis (with thread dumps and cpu stats to start with along with PegaRule/PegaAlert logs) - feel free to contact Pega GCS if you have collected the requested data. The article referenced can be helpful, but nothing is conclusive without detailed analysis. Also do you have a lower environment that can reproduce the issue? That would be a big step in troubleshooting the root cause.