The Fog of War tool doesn’t work for me

I choose the keys to activate the tool, click OK in the menu, but when I press the key I chose to activate and apply the fog, nothing happens. I just keep using the mouse to select objects, etc., but there’s no Fog of War.

• Open the other settings

• select the keys for "fill" and "remove" the Fog of War

• click OK

• go back to build mode
  -press the key I chose to activate the fog
  -but nothing happens. It doesn’t activate; it just keeps drawing blue shapes on the screen

System Details 
TaleSpire Build ID : 8561401b

OS Version: Windows 11 Home Single Language