I've started to notice that when your colonies start to develop their own culture, the name changes back to how it would be in the base game. I think it only affects nations who have a colonial culture within their culture group (like Mexican or Brazilian) For example, "Rio Grande do Sul" with Portuguese culture is changed to "Porto Alegre" with the mod, but when the colonial nation becomes Brazilian, it changes back to "Rio Grande do Sul", which makes the name changes made with the mod kind of pointless as Brazilian culture will always be there. Idk if there is a way to mess with the base game cultures like that, but I think it would make more sense if provinces with colonial cultures kept the same province name as the mother country's culture.
a more ahistorical example is when Portugal colonizes "Rio de la Plata", it changes to "Bons Ventos" with Portuguese culture
but as the colonial nation swaps to Brazilian culture, it changes back to "Rio de la Plata", making the name changes made by the mod kinda pointless

Is there any way to fix this?