Could someone clarify what "Right-click the zone in the tree" means? I am having this problem as well, and tried right-clicking everywhere that might be "the zone in the tree" but can't seem to figure it out.
Ah - okay. Right-click on the 'zone' under the "Playing Now" heading in the app's main screen (ie "Player" or other zones in fancier setups,) then select "Scrobble 'Listening To' ."
Seems like this could be cleaned up a bit. I can see times when maybe I would want some zones not to scrobble, but that's definitely not the default behavior I would expect and it's pretty strange to have it change from an update.