Wrong function called in a 1.N association

Hi experts,

I am facing an issue that I can't figure out.

I will try to simplify my problem to make it understandable:

I have two entities, demand and position.

Each position is link to one demand and a demand can be link to several positions.

Demand's table is stored in a real database, when position is stored in a cluster database. The id of the cluster is saved in demand.

I can't have a direct access to the positions because I need to know the id of the cluster, so all my URL are build this way :

.../DemandSet('0')/PositionSet

But when I call this URL, it calls PositionSet_GetEntity instead of PositionSet_GestEntitySet. Does someone have an explanation?

Really appreciate youre help !

Please let me know if you need more information from me.