Opening balance take on for inventory items

Also new to Manager.
I worked through the guide to set up opening balances for inventory.
I did set my start date.
When entering the qty on an item, all is fine.
I enter the purchase prise as well as the sales price, and then the average purchase cost in the block displayed at the starting balance.
When I hit update, the qty is ok, but the total cost is zero.
When I go back to edit, the prices are all zero.
Is there something else I need to do to rectify this?

If Manager is not saving amounts, maybe you entering them in wrong format. Go to Preferences tab to see what’s the correct format to enter currency amounts.