Somewhat harmless programming error:
After logging in to email account, you will see a number near the email icon which indicates the number of new messages.
After logging off of that account, then logging back in to a second account, there will be no number for new messages for the second account displayed even when there are new messages for that account.
Under the hood, the programming may be looking for IP, and seeing that the icon was clicked already (even though different account), it "thinks" the user has already "seen" the message indicator and so does not display it again.
