diff --git a/lightsim2grid/lightSimBackend.py b/lightsim2grid/lightSimBackend.py
index 461b13d..60a2067 100644
--- a/lightsim2grid/lightSimBackend.py
+++ b/lightsim2grid/lightSimBackend.py
@@ -513,14 +513,13 @@ def make_complete_path(path, filename):
             for i in range(self.__nb_bus_before):
                 self._grid.deactivate_bus(i + self.__nb_bus_before)
             new_orig_to_ls = np.concatenate((orig_to_ls,
-                                             np.zeros(orig_to_ls.shape[0], dtype=orig_to_ls.dtype) + self.__nb_bus_before)
+                                             orig_to_ls + self.__nb_bus_before)
                                             )
             self._grid._orig_to_ls = new_orig_to_ls
         self.nb_bus_total = len(self._grid.get_buses())
         
         # and now things needed by the backend (legacy)
         self._big_topo_to_obj = [(None, None) for _ in range(type(self).dim_topo)]
-        self._aux_finish_setup_after_reading()
         self.prod_pu_to_kv = 1.0 * self._grid.get_buses()[[el.bus_id for el in self._grid.get_generators()]]
         self.prod_pu_to_kv = self.prod_pu_to_kv.astype(dt_float)
         
@@ -530,6 +529,7 @@ def make_complete_path(path, filename):
         bus_vn_kv = np.array(self._grid.get_buses())
         shunt_bus_id = np.array([el.bus_id for el in self._grid.get_shunts()])
         self._sh_vnkv = bus_vn_kv[shunt_bus_id]
+        self._aux_finish_setup_after_reading()
     
     def _aux_setup_right_after_grid_init(self):
         self._handle_turnedoff_pv()
diff --git a/lightsim2grid/tests/test_backend_pypowsybl.py b/lightsim2grid/tests/test_backend_pypowsybl.py
index 4cc8528..bce90c2 100644
--- a/lightsim2grid/tests/test_backend_pypowsybl.py
+++ b/lightsim2grid/tests/test_backend_pypowsybl.py
@@ -114,9 +114,9 @@ def get_casefile(self):
             return "grid.xiidm"
         
         def make_backend(self, detailed_infos_for_cascading_failures=False):
-            return  LightSimBackend(loader_method="pypowsybl",
-                                    loader_kwargs=_aux_get_loader_kwargs_storage(),
-                                    detailed_infos_for_cascading_failures=detailed_infos_for_cascading_failures)
+            return LightSimBackend(loader_method="pypowsybl",
+                                   loader_kwargs=_aux_get_loader_kwargs_storage(),
+                                   detailed_infos_for_cascading_failures=detailed_infos_for_cascading_failures)
                             
     # # add test of grid2op for the backend based on pypowsybl
     # def this_make_backend(self, detailed_infos_for_cascading_failures=False):
diff --git a/lightsim2grid/tests/test_basic_backend_api.py b/lightsim2grid/tests/test_basic_backend_api.py
index c404bad..08a8dde 100644
--- a/lightsim2grid/tests/test_basic_backend_api.py
+++ b/lightsim2grid/tests/test_basic_backend_api.py
@@ -17,17 +17,11 @@
 from lightsim2grid import LightSimBackend
 
 if CAN_PERFORM_THESE:
-    def this_make_backend(self, detailed_infos_for_cascading_failures=False):
-        return LightSimBackend(
-                detailed_infos_for_cascading_failures=detailed_infos_for_cascading_failures
-            )
-    add_name_cls = "test_LightSimBackend"
-
-    res = create_test_suite(make_backend_fun=this_make_backend,
-                            add_name_cls=add_name_cls,
-                            add_to_module=__name__,
-                            extended_test=False,  # for now keep `extended_test=False` until all problems are solved
-                            )
+    from grid2op.tests.aaa_test_backend_interface import AAATestBackendAPI
+    class TestBackendAPI_LSTester(AAATestBackendAPI, unittest.TestCase):        
+        def make_backend(self, detailed_infos_for_cascading_failures=False):
+            return  LightSimBackend(detailed_infos_for_cascading_failures=detailed_infos_for_cascading_failures)
+        
 else:
     print("Have you installed grid2op in dev / editable mode ? We cannot make the `create_test_suite` :-(")
     
diff --git a/src/GridModel.cpp b/src/GridModel.cpp
index 31b0135..2ee2fbb 100644
--- a/src/GridModel.cpp
+++ b/src/GridModel.cpp
@@ -14,8 +14,6 @@ GridModel::GridModel(const GridModel & other)
 {
     reset(true, true, true);
 
-    set_ls_to_orig(other._ls_to_orig);  // set also orig_to_ls
-
     init_vm_pu_ = other.init_vm_pu_;
     sn_mva_ = other.sn_mva_;
 
@@ -23,6 +21,7 @@ GridModel::GridModel(const GridModel & other)
     // 1. bus
     bus_vn_kv_ = other.bus_vn_kv_;
     bus_status_ = other.bus_status_;
+    set_ls_to_orig(other._ls_to_orig);  // set also orig_to_ls
 
     // 2. powerline
     powerlines_ = other.powerlines_;
diff --git a/src/GridModel.h b/src/GridModel.h
index 751a960..85b384f 100644
--- a/src/GridModel.h
+++ b/src/GridModel.h
@@ -49,7 +49,7 @@ class GridModel : public DataGeneric
                 int, // version major
                 int, // version medium
                 int, // version minor
-                std::vector<int>, // ls_to_pp
+                std::vector<int>, // ls_to_orig
                 real_type,  // init_vm_pu
                 real_type, //sn_mva
                 std::vector<real_type>,  // bus_vn_kv