heroes' skills in EotN

im having EotN and Propf and i am little confused after reading the skill unlocking packs faq. is it normaly to be unable to use the skill of my rit. hero xandra after unlocking it!? in the faq it was said all unlocked skill can be used by the heroes regardless the campaign you own , so is it bugged?
i have played the factions and nightfall trials and unlocked some skill but theyre still unable to be used by my heroes

Stuff unlocked from trials are relocked after the trial ends. If you buy those games, the stuff will be unlocked again.
Rough I know.

i know this , but whats disturbing is the faq for the unlocking packs which says the hero can have all unlocked skill, maybe they can have it from the packs only

Skill Unlock Packs, er, unlock skills on your account and are thus available for use by your heroes.