Inexplicable DataflowsStagingWarehouse Load on Capacity

We've recently started seeing entries for "High Scale Dataflow Compute - Warehouse Query" in the Capacity Metric App under Background records.  These were not present a couple months ago and we had a good baseline on the workspace's total compute.  Our dataflows have not changed but suddenly we're seeing a 6% increase in base capacity used under this workspace, attributed to these high-scale entries.

Within this workspace, no dataflows have staging enabled (all queries are italicized), but we are using SQL data destinations so that may be the underlying usage.  I initially thought the billing was just broken out differently in the metric app, but the % base capacity used by the entire workspace has increased by the amount from this line.  It doesn't show under the tooltip for each dataflow either, as NotebookEnjoyer experienced.  The app is no help to narrow this down further.