Some players encounter a black blank map in Crusader Kings III, and also they are having trouble with zooming or moving the map in the game.
If you are also having this problem, you should check out the workaround I shared below.
How to fix black map and zooming issues in Crusader Kings III
Some users say that they solve the map zoom issue by unplugging their controllers. So if you have a USB controller plugged into your PC, you should unplug it. A wireless controller can also cause this problem in Crusader Kings 3.
Examples of USB & wireless controllers: Xbox controller, PS4 DualShock controller, generic gamepad, joystick, racing wheel, pedal
Also, you should update your graphics card drivers to fix the black map issue in CK3. I recommend uninstalling the GPU driver using DDU before installing the new driver.
Hope the issues you are facing get fixed! If the problem still persists, feel free to use the comment box.