Activation manager doesn't connect

Downloaded Nuendo 13 (with download manager) for a trial run but activation manager doesn’t connect (no popups open). Tried all posted solutions -uninstalling/reinstalling, updating security certificate on safari. Still no luck. MacOs 10.15.7 Can someone help?

Did you already have a look at this? Steinberg Activation Manager "Sign In" not working - #22 by SKnapp

Thank you very much, trusting the certificate in keychain worked