A few possibilities -
Is the parent p/m code P by accident? If so, no costs below that would roll up.
Are costs frozen for the parent?
Are you looking at total or lower level costs? TL material costs would be 0.
Is the roll up as of date within the start and end effectiveity dates of the product structure components?
Is the cost report being run for the same site and cost set that was rolled, and an as of date that is after the the roll up?
The parent as set to P/M code was set to P instead of M.
Thank you for your help.