diff --git a/src/snowflake/snowpark/_internal/compiler/cte_utils.py b/src/snowflake/snowpark/_internal/compiler/cte_utils.py
index 1746018c7c9..c075b4fbc77 100644
--- a/src/snowflake/snowpark/_internal/compiler/cte_utils.py
+++ b/src/snowflake/snowpark/_internal/compiler/cte_utils.py
@@ -74,6 +74,12 @@ def traverse(root: "TreeNode") -> None:
             current_level = next_level
 
     def is_duplicate_subtree(encoded_node_id_with_query: str) -> bool:
+        # when a sql query is a select statement, its encoded_node_id_with_query
+        # contains _, which is used to separate the query id and node type name.
+        is_valid_candidate = "_" in encoded_node_id_with_query
+        if not is_valid_candidate:
+            return False
+
         is_duplicate_node = id_count_map[encoded_node_id_with_query] > 1
         if is_duplicate_node:
             is_any_parent_unique_node = any(
diff --git a/tests/integ/test_large_query_breakdown.py b/tests/integ/test_large_query_breakdown.py
index ac9df3b1c2e..67d118012cb 100644
--- a/tests/integ/test_large_query_breakdown.py
+++ b/tests/integ/test_large_query_breakdown.py
@@ -118,7 +118,8 @@ def test_no_valid_nodes_found(session, caplog):
 
 def test_large_query_breakdown_external_cte_ref(session):
     session._cte_optimization_enabled = True
-    if not session.sql_simplifier_enabled:
+    sql_simplifier_enabled = session.sql_simplifier_enabled
+    if not sql_simplifier_enabled:
         set_bounds(session, 50, 90)
 
     base_select = session.sql("select 1 as A, 2 as B")
@@ -153,9 +154,9 @@ def test_large_query_breakdown_external_cte_ref(session):
     assert summary_value["breakdown_failure_summary"] == [
         {
             "num_external_cte_ref_nodes": 2,
-            "num_non_pipeline_breaker_nodes": 4,
+            "num_non_pipeline_breaker_nodes": 4 if sql_simplifier_enabled else 2,
             "num_nodes_below_lower_bound": 28,
-            "num_nodes_above_upper_bound": 1,
+            "num_nodes_above_upper_bound": 1 if sql_simplifier_enabled else 0,
             "num_valid_nodes": 0,
             "num_partitions_made": 0,
         }
@@ -165,7 +166,7 @@ def test_large_query_breakdown_external_cte_ref(session):
 def test_breakdown_at_with_query_node(session):
     session._cte_optimization_enabled = True
     if not session.sql_simplifier_enabled:
-        pass
+        set_bounds(session, 40, 80)
 
     df0 = session.sql("select 1 as A, 2 as B")
     for i in range(7):
@@ -189,6 +190,9 @@ def test_breakdown_at_with_query_node(session):
 
 def test_large_query_breakdown_with_cte_optimization(session):
     """Test large query breakdown works with cte optimized plan"""
+    if not session.cte_optimization_enabled:
+        pytest.skip("CTE optimization is not enabled")
+
     if not session.sql_simplifier_enabled:
         # the complexity bounds are updated since nested selected calculation is not supported
         # when sql simplifier disabled
diff --git a/tests/integ/test_multithreading.py b/tests/integ/test_multithreading.py
index 00fb2e16663..eba8e8b5477 100644
--- a/tests/integ/test_multithreading.py
+++ b/tests/integ/test_multithreading.py
@@ -757,8 +757,7 @@ def process_data(df_, thread_id):
             assert match is not None, query
             file_format_name = match.group()
             unique_create_file_format_queries.add(file_format_name)
-        else:
-            assert query.startswith("DROP  FILE  FORMAT")
+        elif query.startswith("DROP  FILE  FORMAT"):
             match = re.search(r"SNOWPARK_TEMP_FILE_FORMAT_[\w]+", query)
             assert match is not None, query
             file_format_name = match.group()
diff --git a/tests/unit/test_cte.py b/tests/unit/test_cte.py
index 09a1768f282..d2617dd5d86 100644
--- a/tests/unit/test_cte.py
+++ b/tests/unit/test_cte.py
@@ -23,7 +23,7 @@
 def test_case1():
     nodes = [mock.create_autospec(SnowflakePlan) for _ in range(7)]
     for i, node in enumerate(nodes):
-        node.encoded_node_id_with_query = i
+        node.encoded_node_id_with_query = f"{i}_{i}"
         node.source_plan = None
         if i == 5:
             node.cumulative_node_complexity = {PlanNodeCategory.COLUMN: 80000}
@@ -39,7 +39,7 @@ def test_case1():
     nodes[5].children_plan_nodes = []
     nodes[6].children_plan_nodes = []
 
-    expected_duplicate_subtree_ids = {2, 5}
+    expected_duplicate_subtree_ids = {"2_2", "5_5"}
     expected_repeated_node_complexity = [0, 3, 0, 2, 0, 0, 0]
     return nodes[0], expected_duplicate_subtree_ids, expected_repeated_node_complexity
 
@@ -47,7 +47,7 @@ def test_case1():
 def test_case2():
     nodes = [mock.create_autospec(SnowflakePlan) for _ in range(7)]
     for i, node in enumerate(nodes):
-        node.encoded_node_id_with_query = i
+        node.encoded_node_id_with_query = f"{i}_{i}"
         node.source_plan = None
         if i == 2:
             node.cumulative_node_complexity = {PlanNodeCategory.COLUMN: 2000000}
@@ -65,7 +65,7 @@ def test_case2():
     nodes[5].children_plan_nodes = []
     nodes[6].children_plan_nodes = [nodes[4], nodes[4]]
 
-    expected_duplicate_subtree_ids = {2, 4, 6}
+    expected_duplicate_subtree_ids = {"2_2", "4_4", "6_6"}
     expected_repeated_node_complexity = [0, 0, 0, 0, 2, 8, 2]
     return nodes[0], expected_duplicate_subtree_ids, expected_repeated_node_complexity