diff --git a/tensordict/_td.py b/tensordict/_td.py
index d18e37e39..619c06b2b 100644
--- a/tensordict/_td.py
+++ b/tensordict/_td.py
@@ -860,7 +860,11 @@ def __setitem__(
         if isinstance(value, (TensorDictBase, dict)):
             indexed_bs = _getitem_batch_size(self.batch_size, index)
             if isinstance(value, dict):
-                value = self.from_dict_instance(value, batch_size=indexed_bs)
+                value = self.from_dict_instance(
+                    value, batch_size=indexed_bs, device=self.device
+                )
+            elif value.device != self.device:
+                value = value.to(self.device)
                 # value = self.empty(recurse=True)[index].update(value)
             if value.batch_size != indexed_bs:
                 if value.shape == indexed_bs[-len(value.shape) :]:
@@ -883,7 +887,7 @@ def __setitem__(
             for value_key, item in value.items():
                 if value_key in keys:
                     self._set_at_str(
-                        value_key, item, index, validated=False, non_blocking=False
+                        value_key, item, index, validated=True, non_blocking=False
                     )
                 else:
                     if subtd is None:
@@ -3129,6 +3133,7 @@ def _exclude(
         #     self._maybe_set_shared_attributes(result)
         return result
 
+    # @cache
     def keys(
         self,
         include_nested: bool = False,