I created a sheet with these country names:
United Kingdom Spain Portugal Germany France Netherlands Belgium Poland Czech Republic Slovakia
I then selected the cells and hit the Geography button.
In the neighbouring cells I entered the formula =A1.Image, repeating for each cell, which displayed the flag for those countries.
France was not displayed, but I can fix that by selecting the France cell, opening the menu and going Data Type > Change and choosing the flag which shows up. This updates France to Metropolitan France, which fixes the problem for France.
Belgium, Czech Republic and Slovakia still show #FIELD!.
The same fix for those cells does not work and I can't find an option to import or update/refresh the missing flags (that works.)
How do I fix these?