Path finder unaffected by slow passive would love others input

I'm not 100% sure but the spider mobs you encounter in act 2 seem to be able to slow you still with that web they spit even with the passive to make you unaffected. I'm not sure if it's my mind playing tricks on me though would love if some others could test this out as well. I happen to notice when I was in maps but not sure how much the slow is from the ac 2 mobs and the ones in t14's as well.