Can you provide steps to reproduce?
I did turn on a new feature with slick stream (service that powers search and the heart icons). Instead of only offering a slick stream account, it's supposed to offer the ability to log in with Google to save favorites. My understanding is that it should only prompt for a Google login if you're trying to favorite an article....
Rationale: should increase email newsletter subscriptions due to less friction to sign up and will help future ad revenue as cookies disappear.