Your statement does not make sense. Poland being occupied does not mean no Poles were anti-semites. And what about anti-Semitism after WW2?
There’s a big difference between being anti-Semitic and being willing to kill. The first group to put up placards denouncing German brutality towards Jews in Cracow was a right wing Catholic group that had called for Poles to boycott Jewish businesses before the war. If you read “Ordinary Men” about a German MP unit charged with liquidating Jews it’s quite clear that most Poles dragged their feet as much as possible to avoid helping the Germans, and many were shot for actively hiding them or helping Jews who were hiding. They may not have liked Jews, but they were not going to be accessories to murder if they could avoid it, and the Germans complained a lot about it.
Polish anti-semitism after WWII is a different beast - it was not collaboration with the Nazis. It was not sending Jews to death camps. It was not as bloody (though the death of even 1 person to prejudice is 1 too many). The topic here was the FBI accusing the Polish government of collaborating with the Nazis