What I have seen is a confusion (perhaps intentional) between anti-semitism, and protesting Israel’s behavior since the Hamas attack in October.
Criticizing Israel’s response is not anti-Semitism- it is literally just criticizing the response.
Of course, a lot of criticism of Israel is rooted in antisemitism. But saying all criticism of Israel is antisemitic deflects legitimate criticism, and makes it harder to identify legitimate antisemitism.