Thanks Chul - the post was very helpful!
I did find out how its calculating the YTD amounts - OneStream is summing the product of the periodic amounts and the consolidation percentages for each period. Its showing the correct YTD and periodic amounts for every month we have actuals - so our remaining issue is for the remainder of the year (Jun-Dec) and only on the structures that were updated, there are derived amounts on the parents that are the sum of the periodic amounts for Jan-May. Our No Data Zero View for Non Adjustments on the Actual scenario is set to YTD, so the base and child members of the hierarchy are summing up to zero in Jun with the derived amounts, except for the parents where the percent consolidation stored item is applied. What would cause the YTD amount to not equal zero for Jun-Dec in this situation?