I am currently using a build Vlado send me a while ago where he fixed a problem with the scattervolume shader (3.57.01),
so I am not sure if its the same in the current live builds.
Anisotropy has no effect on the material with GGX enabled. Ward etc. works fine.
Looks fine, but just to be sure please send me a simple scene at peter.matanov@chaosgroup.com
Thanks Peter for getting back to me. You can delete this thread if possible. After a recent reboot everything works fine again. I have no idea what changed. 