That they are rabidly pro-Israel while simultaneously glorifying Hitler and indulging in conspiracy theories of Jewish domination certainly lends credence to the idea that anti-Zionism ≠ antisemitism
Because Israel is their wet dream: an ethno-suprematist country, with right to self-determination only for the majority group, that seeks for lebensraum and shoots anyone who opposes it.
Frankly, I think their supposed "antisemitism" is a joke compared to their anti-Arab and anti-muslim attitude. Those are their real enemies now.
Its actually quite simple:
They hate Jews
They really hate muslims
One can be an anti-Semite ("Jew hater") and pro-Zionist ("Israel supporter") at the same time: "I hate them so much that I want them out of my country and into their own country".
This however speaks nothing of anti-Zionism.