diff --git a/apps/appreciation/ui_views.py b/apps/appreciation/ui_views.py
index 2ab3c2f..9154751 100644
--- a/apps/appreciation/ui_views.py
+++ b/apps/appreciation/ui_views.py
@@ -63,6 +63,11 @@ def appreciation_list(request):
         queryset = queryset.none()
 
     status_filter_val = request.GET.get("status", "")
+    # Guard: silently reset unknown/legacy status values (e.g. a bookmarked
+    # ?status=acknowledged from before the 3-state collapse) to "all" so the
+    # user doesn't see an unexplained empty list.
+    if status_filter_val and status_filter_val not in dict(AppreciationStatus.choices):
+        status_filter_val = ""
     if status_filter_val:
         queryset = queryset.filter(status=status_filter_val)
 
diff --git a/apps/observations/test_workflow_realignment.py b/apps/observations/test_workflow_realignment.py
index 884cf86..ccee539 100644
--- a/apps/observations/test_workflow_realignment.py
+++ b/apps/observations/test_workflow_realignment.py
@@ -67,3 +67,43 @@ class TestObservationDepartmentResponsePermission(TestCase):
         )
         assert response.status_code == 302, \
             f"dept_manager of other dept should be redirected (denied), got {response.status_code}"
+
+
+@pytest.mark.django_db
+class TestObservationDetailRespondButtonGate(TestCase):
+    """The 'Submit Response' button must be visible to dept_manager of the
+    assigned department — not just pass the view's permission check.
+
+    Locks in the fix for the Important issue found in whole-branch review:
+    Task 2 added dept_manager to the view predicate but the template context
+    var `can_respond_to_department` was missed, so the button stayed hidden.
+    """
+
+    def setUp(self):
+        self.hospital = Hospital.objects.create(name="Test Hospital Gate", code="TH04")
+        self.dept = Department.objects.create(name="Dept Gate", hospital=self.hospital, code="GT")
+
+        _ensure_group("Department Manager")
+        self.dept_manager = User.objects.create_user(
+            username="gdmgr", email="gdmgr@test", password="x", department=self.dept
+        )
+        self.dept_manager.groups.add(Group.objects.get(name="Department Manager"))
+
+        self.observation = Observation.objects.create(
+            description="Gate test observation",
+            hospital=self.hospital,
+            assigned_department=self.dept,
+            sent_to_department=True,
+            department_responded_at=None,
+            status="in_progress",
+        )
+
+    def test_dept_manager_sees_respond_button(self):
+        """The department detail page renders the respond control for dept managers."""
+        self.client.force_login(self.dept_manager)
+        response = self.client.get(
+            reverse("observations:observation_detail", kwargs={"pk": self.observation.pk})
+        )
+        assert response.status_code == 200
+        assert response.context["can_respond_to_department"] is True, \
+            "dept_manager of assigned dept must see can_respond_to_department=True"
diff --git a/apps/observations/views.py b/apps/observations/views.py
index 91d38fa..0f3dbb5 100644
--- a/apps/observations/views.py
+++ b/apps/observations/views.py
@@ -653,7 +653,7 @@ def observation_detail(request, pk):
         "can_triage": user.has_perm("observations.triage_observation") or user.is_px_admin() or user.is_px_employee(),
         "can_convert": user.is_px_admin() or user.is_hospital_admin() or user.is_px_management() or user.is_px_employee(),
         "can_send_to_department": user.is_px_admin() or user.is_hospital_admin() or user.is_px_management() or user.is_px_employee() or user.is_department_manager() or user.is_px_management(),
-        "can_respond_to_department": user.is_px_admin() or user.is_hospital_admin() or user.is_px_management() or user.is_px_employee() or (user.is_champion() and observation.assigned_department == user.department),
+        "can_respond_to_department": user.is_px_admin() or user.is_hospital_admin() or user.is_px_management() or user.is_px_employee() or (user.is_champion() and observation.assigned_department == user.department) or (user.is_department_manager() and observation.assigned_department == user.department),
         "can_send_reminder": user.is_px_admin() or user.is_hospital_admin() or user.is_px_management() or user.is_px_employee(),
         "can_delete": user.is_px_admin() or user.is_hospital_admin() or user.is_px_management() or user.is_px_employee(),
         "can_admin": user.is_px_admin() or user.is_hospital_admin() or user.is_px_employee(),