Sum does not count correctly if you count a date

[christian.koenig]

Hello Community, I have the following problem.

Within a report I have a list that counts me a date (column: Ein "all"). The second column does exactly the same count but with respect to a date picker: (Column: "Ein"). If I now cut out of the list the date display (column Ein-/Ausgangsdatum), the result is not calculated correctly: (see attachment)

I hope an expert here can help me quickly.
Enclosed the formulas of the individual columns

Ein All:   count([Geschäftsfall].[GF-Daten].[Ein-/Ausgangsdatum])
Ein:       IF ([Ein-/Ausgangsdatum] between ?p_datumvon? and ?p_datumbis? ) THEN     ( [Ein - Count All])  ELSE      (0 )

thx Chris