@sharpdrivetek check the latest version (20.5.89) and go to
Inventory Items tab.
If you have multi-stage production process, Manager will now check your inventory items whether production stage is set correctly for each item and if not, you will see alert like this:
When you click on the alert, you will see list of inventory items. Their current production stage and “required” production stage. You will need to edit inventory items where production stage is lower than required and set it to required or higher.
This would fix inventory cost issue. So I don’t think this is a bug, for multi-stage production, the correct production stage needs to be set so production orders are executed in the correct order and inventory cost can flow between them properly.
Manager doesn’t support circular production orders. You cannot have Item A which is used to produce Item B and then have another production order which is using Item B to produce Item A. If you enter production orders like this, Manager will forever complain about inventory items which need their production stage elevated because production stage of input items must be always lower than production stage of output items and circular production orders make this impossible.