I accidentally clicked on the Restore Down icon in the top-right corner of the docked Command Window at the bottom of my screen and it disappeared.

Now if I type Ctrl+9 I get a message window "Closing the command window means you will no longer see command line feedback.  Once closed, pressing Ctrl+9 will display the command window again.  Do you want to proceed? Yes No".

Whether I say Yes or No, then type Ctrl+9 again - the Command Window does not return.

I can get the floating Command Window using F2, but I don't want that obscuring my workspace.

How do I re-maximise the docked Command Window?