Activity Monitor columns missing

My Activity Monitor does not have any columns that show more details about each process.

I've already ensured that under "View" in the menu bar, the relevant columns are enabled.

You can reset your Activity Monitor settings by quitting Activity Monitor, and then deleting the preferences file, and any preferences lock files, and then re-opening the app.

Open Terminal and paste in the following command:

rm ~/Library/Preferences/com.apple.ActivityMonitor.plist*

(Note the * at the end to delete com.apple.ActivityMonitor.plist.lock and com.apple.ActivityMonitor.plist.)

Hit enter, and reopen Activity monitor - the columns should now be present.

The "Process Name" column is too big, causing it to crowd out the other columns pushing them to the right side. You can manually resize the "Process Name" column by enlarging the Activity Monitor window, scrolling far to the right, and then dragging the column separator between "Process Name" and the next column back to the left so that the column is standard size again.

This problem happened to me after a Catalina update. For whatever reason, the default size of that column was changed by the update causing this to occur.