I think part of the problem is that for the longest time antisemites had to rely on complete lies to push their propaganda, which mostly worked best when there was a crisis that could be blamed on “the Jews”. The current actions of the Israeli government does two things: firstly it causes valid criticism of these actions and secondly it allows antisemites to use this valid criticism to push their antisemitic views but this time having to lie less (note that there are still lies involved and blaming the entirety of the Jews for anything the Israeli government does is obviously bullshit).

So I agree with you: The actual reason for a rise in antisemitism is not the Israeli government. But the current actions of the Israeli government help antisemites push their views. These two things often get conflated into the statement “Israel is causing antisemitism”.