VBAPanel lists all macros from all files ever opened, they are not possible to remove

There is a bug in Excel (Office 365, most recent version) wherein the Visual Basic for Applications lists all macros from all files ever opened, they are not possible to remove.

See the attachment for a screenshot showing multiple projects being listed in the panel, the files they are associated with are closed, they are not possible to remove as indicated by the greyed-out "Remove" context menu item.

Assistance is appreciated.