Northmen in Scandinavia disappear for seemingly no reason. Choctaw seems to be the only North American Nation along with Iroquois/Player that gets Chinese Tech Bonus. Denmark, England, Scotland, Norway, Sweden, Samiland, Mehmed's Nomads and the Band remain OPM (One Province Minor) for at least hundred years, not expanding through an event or through AI Colonization at all. Also, Switzerland region doesn't seem to have any Trade Goods once colonized.

I played with Complete Map and Cultural Diffusion mods at the time of most bugs, as Ruma and Tirol. I played with The United Federation mod in North America as The United Federation (which unites Iroquois and Huron), so that might have something to do with China Tech bug.