@DAVESHADY: I'm not too familiar with Google Discover, I'm afraid. If you're using the Google app, can you try accessing Google via an alternate browser, such as Samsung Internet, to see if the Discover options are any different. I did find out that the heart symbol allows you to 'like' a topic, and you can find/edit your likes via google.com/search/contributions/reactions
What I'd suggest is reaching out to Google Support for further clarification on this, as it may be the case that the Follow + button has been moved in a recent update.
