Resolving issues with preloading
Preloading the cache can cause load issues on slower servers. If you find your server suffering CPU spikes, or if you see a blank page randomly after having updated content, changing your preload settings will likely solve those issues.
Preload not working at all? Follow the steps in this tutorial:
Preload cache is not working
Disable preload bot
Sometimes the preload bot can cause a spike in CPU usage or server load, especially if your homepage displays a great number of links that the preload bot then will attempt to visit.
You can turn off both of the bot directly in the Preload settings tab:
Heads up, developers! You can disable the preload bot programmatically like this:
add_filter( 'do_run_rocket_bot', '__return_false' );