Pyqt6 bug with QSqlRelationalTableModel and Postgresql (version 13)

Question

The following code works perfectly with Sqlite3 but not with Postgres. No bug but the returned table is always empty...

self.model = QSqlRelationalTableModel(db=db)        
self.model.setTable("hr_employee")
self.model.setRelation(2, QSqlRelation("Job", "job_id", "name"))
self.model.select()
self.table.setModel(self.model)

if I remove this line, it works !

self.model.setRelation(2, QSqlRelation("Job", "job_id", "name"))

I would appreciate any help because I am stuck.