Power Query background refresh disables preview refresh for SharePoint folder

Put a few CSV files in SharePoint then I Get Data and choose SharePoint Folder as the source and then combine the file contents into one table. Put another file into the SharePoint Folder and then in the Edit Query window click the Refresh Preview button. It picks up the new file.

Now go to Options > Current File > Data Load > uncheck "Allow data preview to download in the background"

Put another file in the SharePoint folder and go back to the Edit Query dialog and click Refresh Preview. Note it does not pick up the new file now.

In summary, that setting appears to do more than intended on SharePoint Folder sources. However on (local file system) Folder sources it continues to allow preview refresh properly. Please fix the impact on SharePoint Folder preview refresh.