new additions to child theme css not reading

Hello, I have a Catch Kathmandu Pro child theme with an extensive css file that works fine ... but recently anything I add to the file does NOT read on the website, instead I have to put it into "Custom CSS" which I'd rather not do. So far I've tried different browsers, deactivating plugins, using !important; and rebooting the computer but no success. Any ideas? (Site is not live yet so I can't give you a URL.) Thanks