diff --git a/apps/accounts/serializers.py b/apps/accounts/serializers.py
index 66c665fc..c90ffef4 100644
--- a/apps/accounts/serializers.py
+++ b/apps/accounts/serializers.py
@@ -115,10 +115,20 @@ class UserSerializer(serializers.ModelSerializer):
         channel_profiles = validated_data.pop("channel_profiles", None)
 
         # Merge custom_properties instead of replacing (prevents data loss)
+        # Strip null values — sending null for a key omits it rather than overwriting with null
         custom_properties = validated_data.pop("custom_properties", None)
         if custom_properties is not None:
             existing = instance.custom_properties or {}
-            instance.custom_properties = {**existing, **custom_properties}
+            cleaned = {k: v for k, v in custom_properties.items() if v is not None}
+            merged = {**existing, **cleaned}
+            # Scrub stale nav IDs so the DB self-heals on next save
+            for nav_field in ('navOrder', 'hiddenNav'):
+                if nav_field in merged and isinstance(merged[nav_field], list):
+                    merged[nav_field] = [
+                        item for item in merged[nav_field]
+                        if item in VALID_NAV_ITEM_IDS
+                    ]
+            instance.custom_properties = merged
 
         for attr, value in validated_data.items():
             setattr(instance, attr, value)
diff --git a/frontend/src/store/auth.jsx b/frontend/src/store/auth.jsx
index 8f0362c7..6d36e88c 100644
--- a/frontend/src/store/auth.jsx
+++ b/frontend/src/store/auth.jsx
@@ -8,6 +8,7 @@ import useUserAgentsStore from './userAgents';
 import useUsersStore from './users';
 import API from '../api';
 import { USER_LEVELS } from '../constants';
+import { DEFAULT_ADMIN_ORDER, DEFAULT_USER_ORDER } from '../config/navigation';
 
 const decodeToken = (token) => {
   if (!token) return null;
@@ -76,7 +77,13 @@ const useAuthStore = create((set, get) => ({
 
   getHiddenNav: () => {
     const user = get().user;
-    return user?.custom_properties?.hiddenNav || [];
+    const hiddenNav = user?.custom_properties?.hiddenNav || [];
+    // Filter out stale IDs that are no longer valid for this user's role
+    const isAdmin = user?.user_level >= USER_LEVELS.ADMIN;
+    const validIds = new Set(
+      isAdmin ? DEFAULT_ADMIN_ORDER : DEFAULT_USER_ORDER
+    );
+    return hiddenNav.filter((id) => validIds.has(id));
   },
 
   toggleNavVisibility: async (itemId) => {