Unit price in price list without base price

Hi all.

I can't find answer for my situation.

I have B1 8.81 pl 09.

Price list based on Last Purchase Price with Factor = 1

In price list I see items with unit price, but without base price. The item has no any moving. It was created a month ago.

Checkbox "Manual" is not active.

How is it possible? How the unit price can appear in price list with this conditions. I mean standart processes in SAP, no DI API.

Thanks.