Board Thread:Plants vs. Zombies 2: It's About Time/@comment-24508466-20140216121036/@comment-24275721-20140516064157

PnFforever wrote: (facepalm) I tried to obtain a star in Pirate Seas in the Chinese version but......I've already protected the flowers from the zombies but still doesn't give me a star!. It thinks I failed to do so!!! (internal rage). There was a bug like that (where the star won't appear for the flower challenges) but it's fixed in the latest version.

Maybe you are still playing the older version; that's why you still have the bug. Get the latest version.