diff --git a/project.env b/project.env
index ee673b8..1ea90ce 100644
--- a/project.env
+++ b/project.env
@@ -3,7 +3,7 @@ PROJECT_NAME="stellars-jupyterhub-ds"
 PROJECT_DESCRIPTION="Multi-user JupyterHub 4 deployment platform with data science stack, GPU auto-detection, NativeAuthenticator, and isolated per-user environments spawned via DockerSpawner"
 
 # Version
-VERSION="3.6.22_cuda-13.0.2_jh-5.4.2"
+VERSION="3.6.23_cuda-13.0.2_jh-5.4.2"
 VERSION_COMMENT="Standardize env vars with JUPYTERHUB_ prefix, admin settings page"
 RELEASE_TAG="RELEASE_3.2.11"
 RELEASE_DATE="2025-11-09"
diff --git a/services/jupyterhub/conf/bin/custom_handlers.py b/services/jupyterhub/conf/bin/custom_handlers.py
index e93bdd4..93a4016 100755
--- a/services/jupyterhub/conf/bin/custom_handlers.py
+++ b/services/jupyterhub/conf/bin/custom_handlers.py
@@ -624,9 +624,9 @@ class SessionInfoHandler(BaseHandler):
 
             self.log.info(f"[Session Info] {username}: base_timeout={timeout_seconds}s ({timeout_seconds/3600:.1f}h), extensions={extensions_used_hours}h, effective_timeout={effective_timeout}s ({effective_timeout/3600:.1f}h)")
 
-            # Get last activity timestamp from SERVER (not user - user.last_activity updates on Hub access)
-            # The idle culler uses server.last_activity, so we must use the same
-            last_activity = spawner.server.last_activity if spawner.server else None
+            # Get last activity timestamp from SPAWNER (not user - user.last_activity updates on Hub access)
+            # The idle culler uses spawner.last_activity, so we must use the same
+            last_activity = spawner.orm_spawner.last_activity if spawner.orm_spawner else None
             if last_activity:
                 from datetime import datetime, timezone
                 now = datetime.now(timezone.utc)
@@ -753,8 +753,8 @@ class ExtendSessionHandler(BaseHandler):
         # Calculate new time remaining: base timeout + ALL extensions - elapsed
         extension_seconds = new_total_extensions * 3600
         effective_timeout = timeout_seconds + extension_seconds
-        # Use server.last_activity (not user - matches what idle culler uses)
-        last_activity = spawner.server.last_activity if spawner.server else None
+        # Use spawner.last_activity (not user - matches what idle culler uses)
+        last_activity = spawner.orm_spawner.last_activity if spawner.orm_spawner else None
         if last_activity:
             now_utc = datetime.now(timezone.utc)
             last_activity_utc = last_activity.replace(tzinfo=timezone.utc) if last_activity.tzinfo is None else last_activity