Vassals switching cultures is annoying af

[Nick]

You look away from you vassal for 10 years and suddenly the livonian order converted the baltics to estnian culture.
You switch navarra, galicia, aragon etc. to castilien culture and when get their liberty desire back to normal states they have flipped back.
I hope they fix it with the introduction of vassal contracts.
I thought the game is finally in a good state with 1.4, but it is still annoying and needs another patch.