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.
Who is saying this? All I've heard are people on one side insisting that people are saying this, sounds like a straw man
[1]: https://en.wikipedia.org/wiki/Criticism_of_Israel#Suppressio...