periodic cost update transaction with incorrect distributions

We are using Periodic Average Costing (PAC) for one Operation Unit. We did a periodic cost update transactions to some items with the option "Inventory Value Change".

But these transactions affected the cost element "Material Overhead". We don't use this cost element "Material Overhead".

We have validated the PAC distributions, and the distributions affected the material overhead. We did the periodic cost update transactions to another items and it didn't affect this element cost.

We need to know why these periodic cost update transaction affect this cost element?