Most of the examples of antisemitic repression in Poland took place during the post-partition era in the 19th century, when Poland was ruled by Russia, and Poles themselves faced similar repression by the Russian authorities.
2. As for Bulgaria...not deporting Jews to their death for one small period of time != lack of antisemitism in the past few hundred years.
According to the USHMM,[1] Bulgaria's actions in World War Two included:
Instituting laws that, among other things, forbid Jews from marrying non-Jews and restricted where Jews could live and what jobs they could have.
Deporting Jews who were not in Bulgaria pre-war (its borders expanded) to their deaths.
Sending Jews to slave labor camps. [1]https://encyclopedia.ushmm.org/content/en/article/bulgaria
So, no, Bulgaria was antisemitic in the past few hundred years.
Russians were more aligned with usa tho...