Pivot Table Report error - SM 9.40

I created a report to list interactions (Incidents table) that occurred outside of normal working hours. I built a simple query using the RAD function time() operating on the open.time field.  Works great.

I changed the report to a pivot table (no other changes), and the report fails ( No report data) with subsequent errors, "The 'time()' function is not supported in cross table queries. (display, show.rio)" and "Error parsing the WHERE clause (display,show.rio)".

In troubleshooting, I found I can remove the time() function and the pivot table works, though not presenting the data that I need.

Does anyone have any ideas on how I can solve/troubleshoot further, short of 'use Crystal Reports'?

Thanks much.