Wizard has spark generator and casts force bolt. Force bolt deals 1 damage, and spark generator does not add damage. Force bolt does arcane damage, spark generator should only activate on electrical damage.
Force bolt is arcane, spark generator triggers to make any arcane attacks harder to block (trait has 2 abilities - one for electrical, one for arcane). Not a bug.
Considering the amount of people who bug report this issue I'm pretty sure you're correct. They recently changed all arcane art to differentiate it from electric - might need to rewrite the rule tex to be more obvious as well. Maybe space the 2 rules apart?
You do have to read the card as it stands: However, there's not enough room to separate the rules any more than they are already.
Problem is that the lines break at the edge of the card, so a / wouldn't contrast very well, I think. Perhaps bolding the Electrical and Arcane words?
How about three boxes instead of two? Trait. Attach this card to yourself. Duration 3. Add 2 damage to Electrical attacks you play. Keep. Subtract 3 from Block rolls against Arcane attacks you play. Keep. We have room for another line of text and a break between boxes. Or just drop the arcane part altogether.