13 colonies - For sale ?

I am playing the Grand campaign as British. On Turn 10 Falmouth and Boston have suddenly become French ( I am at peace with France ). No invasion or war , they are now French.

I can only imagine that they were traded to France by the 13 Colonies in return for technology , totally ridiculous that a protectorate can do this.

I wouldn't be surprised, the AI really overates technology, I think it is because a human player could abuse the diplomacy system by swapping techs.

The USA has appeared before I've incorporated the 13 Colonies, which is pretty annoying!