Sorry for the lengthy title, I'll elaborate. I love the fact that I can be on Stackoverflow and get notifications about a question on programmer.stackexchange, and vice versa, but I've realized that this doesn't happen the next day.
For example, if I ask a question on superuser and lounge at Stackoverflow, I'll get the alert when someone replies. If, however, I ask a question, turn my computer off and go to sleep, and then open Stackoverflow the next day, I don't get the notification until I go to superuser.
Is this intentional or a bug?