diff --git a/ax/adapter/transfer_learning/adapter.py b/ax/adapter/transfer_learning/adapter.py
index 676f70ad46d..87ada7e43d4 100644
--- a/ax/adapter/transfer_learning/adapter.py
+++ b/ax/adapter/transfer_learning/adapter.py
@@ -788,8 +788,10 @@ def transfer_learning_generator_specs_constructor(
             model's input constructor.
         fit_tracking_metrics: Whether to fit the generator on tracking metrics. Passed
             to the `TransferLearningAdapter`.
-        additional_generator_kwargs: Additional kwargs to be passed
-            to the BoTorchGenerator
+        additional_generator_kwargs: Additional kwargs to be passed to each
+            BoTorchGenerator. When model selection is enabled, these kwargs must be
+            compatible with both the transfer learning model and the single-task
+            fallback.
 
     Returns:
         A tuple containing BOTL generator specs in case model selection is not enabled,
@@ -839,7 +841,10 @@ def transfer_learning_generator_specs_constructor(
     ]
     if use_model_selection:
         botl_specs.append(
-            GeneratorSpec(generator_enum=Generators.BOTORCH_MODULAR),
+            GeneratorSpec(
+                generator_enum=Generators.BOTORCH_MODULAR,
+                generator_kwargs=additional_generator_kwargs,
+            ),
         )
         best_model_selector = SingleDiagnosticBestModelSelector(
             diagnostic="Rank correlation",
diff --git a/ax/analysis/plotly/surface/contour.py b/ax/analysis/plotly/surface/contour.py
index c38b5f3962d..35ce149921d 100644
--- a/ax/analysis/plotly/surface/contour.py
+++ b/ax/analysis/plotly/surface/contour.py
@@ -384,9 +384,9 @@ def _prepare_plot(
 
     fig = go.Figure(
         data=go.Contour(
-            z=z_values,
-            x=z_grid.columns.values,
-            y=z_grid.index.values,
+            z=z_values.tolist(),
+            x=z_grid.columns.tolist(),
+            y=z_grid.index.tolist(),
             colorscale=METRIC_CONTINUOUS_COLOR_SCALE,
             showscale=True,
             colorbar={