Warden nature walk does not give root immunity on PVP servers, even in raid dungeons. It seems to be stuck in PVP mode at all times ( which reduces slow effects by a ridiculously small amount ). Right after the COE patch it was working (along with size reduction potions) and then it got changed back. It's not a big deal but some raid encouters root the MT and it would be nice if it was fixed.
Devs get around root/knockback immunity by calling the same effect something else. For example, Dragons do a thing called 'gravity-flux', which throws you back but 'isn't a knockback, it's a g-flux' (/roll eyes). It's not working on things it worked on before? Or on new content?