Here’s what the ALL ACTIVITY page looks like for this new user when I visit it directly from the usercard - note the blue line with no text in it. It should say something like NO ACTIVITY in that blue line.
Here’s the same ALL ACTIVITY page after selecting REPLIES and then selecting ALL again. Note it says NO REPLIES in the blue line on the ALL ACTIVITY page. The same behavior happens when switching to any of the other menu items and then switching back to ALL - except for TOPICS.