She has always had the bond with Chiton.
And I have seen her lose her powers by multiple means, and that is canon, necklaces, characters cancel powers in many ways and they are not theories, they are facts embodied in the comics.
There are also many characters with whom her powers do not work well or do not work at all.
On an island full of hundreds of mutants, I don't think there aren't several with which Wanda's powers won't work.