Hi Lukas,
thank you for the screenshots.
i don't see all of the Pivot selections, but i'm assuming the DocEntry dimension is not filtering out the value of '390', so for '392' the amounts agree, but for some reason '390''s amount of '1,000' is not being displayed in the pivot results. if this is true i would raise the incident with SAP support to find out if they are aware of the issue.
have you tried filtering specifically for '390'? is it not available in the list of values for the filter?
rgds,
greg