High CPU usage
If you are experiencing high CPU usage on your site, there are two possible ways WP Rocket could cause this:
Pages are not cached
Make sure that WP Rocket is active and caches your pages:
How to check if WP Rocket is caching your pages
Occasionally some of the options on the File Optimization tab, such as Remove Query Strings, or Minify/Combine can cause high CPU usage in cases where your site has a lot of CSS or JS files. Try disabling these options and then monitor your CPU usage to see if it helps.