diff --git a/src/lerobot/rl/gym_manipulator.py b/src/lerobot/rl/gym_manipulator.py
index 8605e224b..b2a1b28c6 100644
--- a/src/lerobot/rl/gym_manipulator.py
+++ b/src/lerobot/rl/gym_manipulator.py
@@ -708,6 +708,20 @@ def control_loop(
         terminated = transition.get(TransitionKey.DONE, False)
         truncated = transition.get(TransitionKey.TRUNCATED, False)
 
+        # DEBUG: trace gripper value through the pipeline.
+        _action_t = transition[TransitionKey.ACTION]
+        _teleop_t = transition[TransitionKey.COMPLEMENTARY_DATA].get("teleop_action")
+        _info_teleop = transition[TransitionKey.INFO].get("teleop_action")
+        _is_intervention = transition[TransitionKey.INFO].get(TeleopEvents.IS_INTERVENTION, False)
+        print(
+            f"[grip-debug] use_gripper={use_gripper} "
+            f"is_intervention={_is_intervention} "
+            f"neutral={neutral_action.tolist()} "
+            f"ACTION={_action_t.squeeze().tolist() if hasattr(_action_t, 'squeeze') else _action_t} "
+            f"comp.teleop_action={_teleop_t.tolist() if hasattr(_teleop_t, 'tolist') else _teleop_t} "
+            f"info.teleop_action={_info_teleop.tolist() if hasattr(_info_teleop, 'tolist') else _info_teleop}"
+        )
+
         if cfg.mode == "record":
             observations = {
                 k: v.squeeze(0).cpu()