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.
Which isn't a one sided phenomenon. The reverse is true as well, where often the most vocal voices rationalizing Israel's actions and behavior around civilian casualties often have anti-Muslim perspectives crop up as back and forth conversation goes on.
One of the litmus tests I've noticed is the capacity to acknowledge and condemn the civilian suffering of both sides. The commenters who recognize and condemn both the Oct 7th terrorist attack and the targeting or indiscriminate killing of civilians in the response to it tend to be rational and level headed driven by humanitarian concerns.
Those who only recognize the suffering of one side and dismiss, dehumanize, or rationalize the suffering of the other side - or worst of all propagandize the denial of it's occurrence or scope - tend to quickly fall into revealing rather abhorrent views with a mere scratching of the surface.
Not everyone who criticizes Israel is antisemitic nor everyone who criticizes Hamas is anti-Muslim, but many who are antisemitic or anti-Muslim seem keen to defend their respective side of the conflict quite emphatically and unilaterally.