Problem Calculation Group displaying default value "-" instead of blank in composite model

Hi all,

I am using in a data model a calculation group with 2 items : 

Item 1 blank > -

VAR DefaultValue="-" VAR Nb = SELECTEDMEASURE() RETURN  if(ISBLANK(Nb),DefaultValue,Nb)

 Item 2 blank > 0

VAR DefaultValue=0 VAR Nb = SELECTEDMEASURE() RETURN  if(ISBLANK(Nb),DefaultValue,Nb)

 It allows me to display a default value instead of "blank".

Everything is OK in the report associated to this datamodel.

I created a composite model on this datamodel and added a table named" Rendez-vous de service" linked to my table "Ordre_Exécution" from the original datamodel

and I experienced the following problem : when i filter my page on a field of the new table and when my selectedmesure returns a blank, the card encounters a problem:

 
instead of

If I create the calculation group in the report based on composite model, there is no problem.

Do you understand why I have his problem and have you a solution to fix it ?

Thank you

Benjamin