Hi TWOSTAGE,
The search area size for explore has been limited due to some fixes that are going on currently. I just tried doing an explore search by entering your username in the explore user name filter and your activities showed up. Please use that filter to do your searches for now.
I attempted this and the last entry that I can see for me is Dec 4 using the Explore Tab. My activities show under Dashboard but do not show under the explore. In my area, Boulder, CO, I cannot see any activities for anyone including me since Dec. 4