Way of Cain bug (Vampirism)

[Junoizes]

On the skill screen it says it should increase my pierce resistance by 26%, yet on my character screen it only shows an increase of 2%.

[ShadowLAnce]

This is part of the "Masteries" mod by the way. Lilith peeps will just send you to the Masteries forum:
http://www.titanquest.net/forums/masteries-mod/

As for the bug I have nothing to contribute. the pierce resist may be a "pierce resist modifier" or you could have pierce resist penalties.