It happens periodically, and if I quit AM and trash /Users/artie/Library/Preferences/com.apple.ActivityMonitor.plist the window is fully populated when I relaunch...no restart necessary.
It's new in Catalina.
The new Great Equalizer is the SEND button.
In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire
