The trick is there are 3 kinds of case: Lowercase, like London Small uppercase, like LONDON Big uppercase, like LONDON. For example, "London" is written "LONDON" on the city banner. If you edit the city name by writing it in uppercase, then city will stay as "LONDON" on the city banner (and not "LONDON"), but everywhere else, it will be written "LONDON" instead of "London". Even if you missclik into edit and leave right away without touching anything, all your "London" in tooltips, timeline... will transform into "LONDON". I guess the game think To correct this, go to your city banner, and write "London" in lowercase. The game will transform automatically all your lowercase into small uppercase (→ it will display "LONDON" and not "London"), but the city's name in the tooltips, timeline... will be revert back to "London" instead of "LONDON". This is how it works in my game. I hope it will work the same for you.