I couldn't find a valid reason this should happen so please correct me if it's not a "bug".   When Seoni casts an attack spell and supplements it with a Blessing of the Gods she gets two additional dice instead of just one.  I couldn't find a scenario, location, or card effect that would cause that to happen.  Also, I may have seen it with another character but I mostly remember it with Seoni.

What was the Blessing showing for the current turn? If it was the one for the skill being checked, you would get two dice. Try clicking on the Blessing symbol at the top of the screen the next time it happens. This is how PACG is supposed to work.