The Project STAFF and ASSIGNMENTS Grid utilizes the 'Totals' and 'Per-Period Metrics' columns.
If the 'Totals' column AND the 'Per-Period Metrics' columns are configured on the grid the CSV Export works as expected and you see all the data.
If you don't have the 'Totals' column configured in the grid, the Export does not work as expected --- all the per-period metrics columns are blank.
STEPS TO REPRODUCE:
NOTE: These steps are for the Project STAFF Grid - repeat the same steps for ASSIGNMENTS grid using any of the metric fields (ETC, ETC Cost, Actuals, Actual Cost)
EXPECTED: to see data in the PER-PERIOD METRICS columns in the CSV output
ACTUAL: the PER-PERIOD cells are blank in the CSV output
WORKAROUND: Add the 'Totals' column to the grid layout before using Export to CSV.
This is caused by Defect DE49460
Clarity PPM 15.x
Defect DE49460 is solved in 15.8.1