Cannot access Edit: Fill Down tool

I have a new stand alone install of P6 8.3 running Windows Sys 7, have had no other issues so far.

The Edit: Fill Down tool is only available in the Project window, not in the Activity window..... except randomly once in a while if I've preselected a list of activities, highlighted the Name field, hit F9 and then select Edit: Fill Down. And then only for one execution.

I've tried with various Grouping criteria and no Grouping, various Sort criteria, and no Sort criteria, tried fill down of Name, Duration Type, Calendar, various Codes or Text fields, no luck.

I've restarted P6, rebooted PC, no luck.