IS Retail: OAPC calculates weird fixed initial quantity, why?

Hi there,

I am planning some initial quantities for articles in WRFAPC01 (create purchasing list) and the system calculates a total quantity per article which does not make sense. I hope someone knows the logic.

Here is the case.

General assortment GA_GROCER has 3 stores assigned to it. Each store (site) has two supplying DCs. I want to initially push 100 units of an article to each of these 3 stores so I enter 100 as initial fixed quantity, but then SAP calculates 400 total quantity (not 300). The question is why? See below 2 screenshots from WRFAPC01 that may clarify my problem.

Thanks in advance.