The formula you posted is a formula for the first period current year net change. It is looking at cell C8 to find the account and department to determine which amount will print. Do you have a valid account/department in cell C8? If so, what is the current year net change for that account? It may be possible that the amount in the data actually is zero.

If you insert a row immediately above this row, this formula does update correctly to $C9. If it doesn't for you, then likly the other issue with the slowness is also hindering the formula updating.

Regards,
Softrak Support