I am using Pentaho 4.8 + Saiku adhoc 1.0, waiting for Saiku version 3.0 to be up and running in Pentaho 5.0

I am quite new to Pentaho and do not know how the SQL query is generated from Saiku Adhoc.
When using a very simple request involving 4 tables, the SQL query created is wrong.
When I test the query in the Query editor of Pentaho Metadata Editor, the result is correct using the 4 tables (so the metadata is good):
Code:
SELECT DISTINCT 
          BT_PIR_PROJET_PIR_PROJET."name" AS COL0
         ,BT_PIR_AXE_PIR_AXE."name" AS COL1
         ,BT_RES_PARTNER_RES_PARTNER."name" AS COL2

FROM res_partner_ordered BT_RES_PARTNER_RES_PARTNER JOIN 
     ( 
      pir_projet_structure BT_PIR_PROJET_STRUCTURE_PIR_PROJET_STRUCTURE JOIN 
      ( 
       pir_projet_ordered BT_PIR_PROJET_PIR_PROJET LEFT OUTER JOIN pir_axe BT_PIR_AXE_PIR_AXE
       ON ( BT_PIR_PROJET_PIR_PROJET.axe_id = BT_PIR_AXE_PIR_AXE.id )
      ) 
      ON ( BT_PIR_PROJET_STRUCTURE_PIR_PROJET_STRUCTURE.projet_id = BT_PIR_PROJET_PIR_PROJET.id )
     ) 
     ON ( BT_PIR_PROJET_STRUCTURE_PIR_PROJET_STRUCTURE.structure_id = BT_RES_PARTNER_RES_PARTNER.id )
When designing the same query with Saiku Adhoc, one table is used twice and one is lacking:
Code:
SELECT DISTINCT 
              BT_PIR_PROJET_PIR_PROJET."name" AS COL0
             ,BT_RES_PARTNER_RES_PARTNER."name" AS COL1
             ,BT_PIR_AXE_PIR_AXE."name" AS COL2
    
    FROM pir_projet_ordered BT_PIR_PROJET_PIR_PROJET JOIN 
         ( 
          pir_projet_structure BT_PIR_PROJET_STRUCTURE_PIR_PROJET_STRUCTURE JOIN 
          ( 
           pir_projet_ordered BT_PIR_PROJET_PIR_PROJET LEFT OUTER JOIN pir_axe BT_PIR_AXE_PIR_AXE
           ON ( BT_PIR_PROJET_PIR_PROJET.axe_id = BT_PIR_AXE_PIR_AXE.id )
          ) 
          ON ( BT_PIR_PROJET_STRUCTURE_PIR_PROJET_STRUCTURE.structure_id = BT_RES_PARTNER_RES_PARTNER.id )
         ) 
         ON ( BT_PIR_PROJET_STRUCTURE_PIR_PROJET_STRUCTURE.projet_id = BT_PIR_PROJET_PIR_PROJET.id )
This means that Postgresql in not able to process the query:
CET ERROR: missing FROM-clause entry for table "bt_res_partner_res_partner" at character 1742

I wonder where the problem comes from (in Saiku or anywhere else) and how to solve it.

Any help is welcome.

Thanks