First off, I use the iOS app; this may only apply here rather than to the PC and Android versions.
Every time I increase the star level of one of my kingdoms, I have noticed that the kingdom name disappears from the emblem on the world map. This persists until I move the map, so roughly 0.2 seconds after the star increase. I don’t have a screen shot of that, unfortunately.
Before today I just assumed that the text wasn’t being drawn by the graphical engine, but this screenshot suggests that something weirder is happening.
This was immediately after I upgraded Drifting Sands from 1 to 2 gold stars. For some reason, the text “Drifting Sands” appears near the kingdom emblem of Divinion Fields; as soon as I moved the map, the text disappeared and moved to the correct location. So the kingdom names are being drawn, just not in the right place.
Weird, but ultimately cosmetic.