On my ranger, I noticed that this Perk works only inside ... Tunnels. Like the Mist Ogre tunnels.
Doesn't work in any other area.
I don't believe it stacks with the other bonuses anyway, last I heard.
It does stack. ONLY in the Mist Ogre tunnels/Undervault and a few other areas, as I said above.
I've noticed this as well... a noticeable increase in speed in tunnels and underground areas as opposed to normal wilderness areas. I wasn't sure if the perk was the problem or not, though.
I can confirm this bug, having the perk but no other speed bonuses. It does indeed only apply in tunnel areas and underground.
Confirmed, worked with me only in Webbed Wood Tunnels, and no where else.
Not sure whether it was only working in tunnels with me, but I did find that the Pathfinder perk wasn't working as intended back when I played Saint Harker.
I also sort of remember it working anywhere I logged into, not sure though.
Bumpity bump!