This has always perplexed me. The tab for Favorites say that there are 4 Favorite questions which had some activity since I last visited this tab. Okay.
I always see some questions get highlighted but they never seem to match the number of questions mentioned on the tab. In this case, only 2 questions are highlighted whereas the tab mentions 4.
As far as I can tell, it tries to highlight the questions with the most recent activity - but what is the criteria if it doesn't always match the number mentioned on the tab.
Is this a bug or by-design? How does highlighting work in the Favorites tab?