.ico in Local Files list shows incorrect icon from another Site

When viewing the Local Files list in DW, the favicon.ico file previews the icon to the left of the file name. This preview/icon is often from a previously opened Site, and not the current Site. It is as if the icon cache was not updated, and showing from a previous session. This has been happening for 5 years at least. Closing DW with the current Site selected, then reopening seems to load the correct icon.