bank nations devastating europe

[Mykhailo Kotsiubynsky]

in my italian run I've conquered all penunsula and banking nations started appearing all around in my country. however, for some reason they were vassal type (maybe they were existing ones and since I've conquered a lot of italian nations they've transferred to be as vassals instead of state banks), but anyway they are refusing to convert into a state bank, they are extremely disloyal (probably because of wealth base I dunno but also because I was running centralization) and they kept to invite all coutnries from Europe to their independence movement. one bank forced me to break an alliance with Austria and France because they were in the movement when bank declared for independence, and I was also fighting named Austria, France plus Hungary, England, Ottomans and Spain - basically every major power. after that I've sold one state bank to each major nation. and noticed that one at a time they each fought same independence movement coalition, which basically devastates country for 10-15 years the coalitions needs to siege them down and get WS to force independence. dunno if I faced some curced timeline where I vassalized state banks because of conquering their parent nations or is this an issue