I've been largely out of the fandom for a while, myself, but not much happened when I was in it that made me uncomfortable, even being Jewish and all.

Years ago I saw a couple of Hellsing cosplayers at conventions wearing shwastikas (when the characters themselves wore them in canon), and there were a couple of people who used to post occasionally in a certain community with jokes that I thought were in very poor taste. But as far as significant amounts of "Nazis are kewlies" sentiment, or a bunch of "It's a joke you guys <3" I didn't really see that, no.