I was listening to a lecture by Robert Garland and he mentioned that Poland was spared from the Black Plague for unknown reasons. Is there any new evidence or hypothesis as to why?
There's a slight problem here - namely, Garland is working off a (very common, admittedly) false premise. More can always be said on the matter if anyone would like to comment further on Poland grappling with the Black Death; for the meantime, OP, here is u/mikedash making a most herculean effort in tracing the story behind 'Poland somehow avoided the Black Death'.
As a further bonus, since you mention it, Mike also has another substantial set of posts on Asia and the Black Death (spoiler alert: it didn't make it that far).