Settings like remove unused CSS, Combine CSS, or improper use of Critical CSS are some settings that may cause issues like this.
The way WP Rockets implements this may be different for each site. It may work seamlessly for some and cause issues for some. It would be best to reach out to WP Rocket for clarification with regards to its implementation.
As is, it seems that WP Rocket removed CSS used for the section in question.
You can try disabling each setting of WP Rocket one by one and see how it goes and to determine which specific setting is causing this.
Hope this clarifies!