Can't access creative cloud app on 2013 iMac running Catalina

When I try accessing Creative Cloud just get the spinning circle and eventually slow to load restart computer/relaunch app and after that goes to check internet and firewall status.  I have uninstalled and reinstalled Creative Cloud and all the Photography plan apps and still have same problem - can access account from a windows laptop. All of the apps now try to connect to the internet on loading and none seem to be able to connect so the whole suit is unusable at present. Spent a total of 3 hours on phone to adobe support - problem not fixed they suggest upgrade MAC OS from Catalina 10.15.7 to new OS which is not an option. Can anybody offer any suggestions/fixes