diff --git a/portal-backend/depmap/breadbox_shim/breadbox_shim.py b/portal-backend/depmap/breadbox_shim/breadbox_shim.py
index 0f218efc..526ac189 100644
--- a/portal-backend/depmap/breadbox_shim/breadbox_shim.py
+++ b/portal-backend/depmap/breadbox_shim/breadbox_shim.py
@@ -9,11 +9,11 @@
     FeatureResponse,
     ValueType,
 )
-from depmap import data_access
 from depmap.data_access.response_parsing import (
     format_breadbox_task_status,
     get_breadbox_slice_id,
     parse_breadbox_slice_id,
+    remove_breadbox_prefix,
 )
 from depmap.interactive.config.categories import CustomCellLinesConfig
 from depmap.vector_catalog.models import Node, NodeType
@@ -233,7 +233,7 @@ def run_custom_analysis(
     or a legacy portal feature (specified with the given feature_data).
     Return a task status.
     """
-    dataset_uuid = parse_breadbox_slice_id(dataset_slice_id).dataset_id
+    bb_dataset_id = remove_breadbox_prefix(dataset_slice_id)
     if slice_query:
         # Temporary hack: for now, this slice query ALWAYS specifies a feature by label.
         # This should always be true for our current feature selection component.
@@ -259,7 +259,7 @@ def run_custom_analysis(
         query_dataset_id = ""
     bb_task_status = extensions.breadbox.client.compute_univariate_associations(
         analysis_type=analysis_type,
-        dataset_id=dataset_uuid,
+        dataset_id=bb_dataset_id,
         query_feature_id=feature_id,
         query_dataset_id=query_dataset_id,
         vector_variable_type=vector_variable_type,
diff --git a/portal-backend/depmap/compute/views.py b/portal-backend/depmap/compute/views.py
index 983c3712..76217f50 100644
--- a/portal-backend/depmap/compute/views.py
+++ b/portal-backend/depmap/compute/views.py
@@ -144,6 +144,7 @@ def post(self):
                 query_cell_lines: list[
                     str
                 ] = legacy_data_slice.index.tolist()  # pyright: ignore
+                slice_query = None
             return breadbox_shim.run_custom_analysis(
                 analysis_type=analysis_type,
                 dataset_slice_id=dataset_id,