pritmadlani Hi
As also suggested earlier in other forum post that JCH Optimize being 3rd party extension has been known to have conflicts so you may try using in-built options 🙂
You may instead try to use Joomla core caching option as outlined in redirection links here and toggle in-built optimize features to enabled in template settings --> advanced settings
You may also view redirection link here if still wishing to go ahead with using JCH Optimize so as to exclude files from compression in which you are facing some issue with Css rule-sets not applying