diff --git a/tests/tasks/uipath-maestro-flow/_shared/test_same_ground_corpus.py b/tests/tasks/uipath-maestro-flow/_shared/test_same_ground_corpus.py
index f934edb576..0c03540220 100644
--- a/tests/tasks/uipath-maestro-flow/_shared/test_same_ground_corpus.py
+++ b/tests/tasks/uipath-maestro-flow/_shared/test_same_ground_corpus.py
@@ -42,6 +42,19 @@
 
 DEBUG_SOLUTION_ALLOWLIST = set()
 
+# The two billing lookups name only a "Data Service entity", which since #3041
+# denotes two node families. Their prompts pin the connector so the graded
+# structure is deterministic; the sibling dispute-resolution task pins it in the
+# same way. Native Data Fabric authoring is covered by its own task, not these.
+CONNECTOR_PINNED_LOOKUPS = {
+    "multi_node/billing_invoice_lookup/billing_invoice_lookup.yaml",
+    "multi_node/billing_discrepancy_detector/billing_discrepancy_detector.yaml",
+}
+CONNECTOR_PIN = (
+    "on the data service `query-entity-records` activity, "
+    "not the native data fabric nodes"
+)
+
 # F1 freezes the #2557 task even though its prompt predates the exact phrase.
 DEBUG_PROJECT_LAYOUT_EXCEPTIONS = {"single_node/coded_agent/coded_agent.yaml"}
 
@@ -192,6 +205,15 @@ def test_debug_graded_prompts_name_a_same_name_solution() -> None:
     assert offenders == DEBUG_SOLUTION_ALLOWLIST | DEBUG_PROJECT_LAYOUT_EXCEPTIONS
 
 
+def test_billing_lookup_prompts_pin_the_data_service_connector() -> None:
+    offenders = {
+        relative
+        for relative in CONNECTOR_PINNED_LOOKUPS
+        if CONNECTOR_PIN not in " ".join(_prompt_text(_task_text(relative)).lower().split())
+    }
+    assert offenders == set()
+
+
 def test_external_graders_use_package_qualified_shared_imports() -> None:
     shared_modules = {
         path.stem for path in (FLOW_TASKS / "_shared").glob("*.py")
diff --git a/tests/tasks/uipath-maestro-flow/multi_node/billing_discrepancy_detector/billing_discrepancy_detector.yaml b/tests/tasks/uipath-maestro-flow/multi_node/billing_discrepancy_detector/billing_discrepancy_detector.yaml
index be39d6ca58..ec7e44c2e7 100644
--- a/tests/tasks/uipath-maestro-flow/multi_node/billing_discrepancy_detector/billing_discrepancy_detector.yaml
+++ b/tests/tasks/uipath-maestro-flow/multi_node/billing_discrepancy_detector/billing_discrepancy_detector.yaml
@@ -43,6 +43,10 @@ initial_prompt: |
     `matchedInvoiceNumber` (string, first ERP row), `accountTier` (string, from
     CRM).
 
+  Build both lookups on the Data Service `query-entity-records` activity, not
+  the native Data Fabric nodes: the tenants this ships to do not all enable
+  them.
+
   Validate the final flow file — the task is not complete until `uip maestro
   flow validate` passes. Grading then runs the flow under debug against live
   tenant data, so build it to actually run, not merely validate.
diff --git a/tests/tasks/uipath-maestro-flow/multi_node/billing_invoice_lookup/billing_invoice_lookup.yaml b/tests/tasks/uipath-maestro-flow/multi_node/billing_invoice_lookup/billing_invoice_lookup.yaml
index d84caaf1c7..4e3f4f26f2 100644
--- a/tests/tasks/uipath-maestro-flow/multi_node/billing_invoice_lookup/billing_invoice_lookup.yaml
+++ b/tests/tasks/uipath-maestro-flow/multi_node/billing_invoice_lookup/billing_invoice_lookup.yaml
@@ -31,6 +31,10 @@ initial_prompt: |
   - Outputs: `matchedInvoiceNumber` (string, first matched row's invoiceNumber)
     and `lineItemCount` (number of rows returned).
 
+  Build the lookup on the Data Service `query-entity-records` activity, not
+  the native Data Fabric nodes: the tenants this ships to do not all enable
+  them.
+
   Validate the final flow file — the task is not complete until `uip maestro
   flow validate` passes. Grading then runs the flow under debug against live
   tenant data, so build it to actually run, not merely validate.