Custom LU , Custom Menu with Transfer child to parent

Hello everyone , 

I have a question close to topic : 

• Custom Menu with Transfer using Persistent Reference fields on Custom LUs

I have 2 custom LU and here are the important fields : 

ParentLU : CF$_Cust_id → Persistant field , reference to  View Customer_info and key customer_id

ChildLu : CF$_ParentCust_id →  Persistant field , reference to view ParentLu and key CF$_CUST_ID

I was able to create a custom menu with transfert from ParentLu  to ChildLu : 

Now , i’m trying to make a menu with custom transfert from Child → Parent lu.

I tried interchanging the destination and source key without sucess.

Is this a key binding issue or a configuration issue of the custom “LU” ?

(I’m unsing app10 UPD10)

Thank you , 

Best regards