Most likely, your website performance suffers from the content you have added to your website. It may happen in case of too many plugins, large not optimized images or other resources. Please check this manual containing detailed instructions on how to optimize your site: https://space.xtemos.com/wordpress-performance-optimization-the-ultimate-guide-in-2021
If you have any questions please feel free to contact us.
You need to disable this option in WP Rocket since it may remove the CSS that is required on the page. So please, disable this option and test how the website works.