Rhino 8 Mac BUG: Export does not supply a default filename

Version 8 (8.3.24009.15002, 2024-01-09)
In previous versions of Rhino, when I chose to Export… or Export Selected…, Rhino would supply a default “Save As:” filename, which was the document name with an extension corresponding to the selected file format.

Now, there is no default filename at all! This is very inconvenient. I hope this wasn’t intentional!