Fortress supports is reducing the damage of Flame Wall, a skill that doesn't Hit

Fortress says the skill deals 30% less damage with Hits.
Flame Wall ignites as if dealt X-Y damage, but it isn't a Hit.

Still, Fortress is reducing its damage.

Felt misleading, even more considering that it is one of the suggested gems for Flame Wall - it's actually awful on it because of this.

yes is this a bug on the tooltip, or is it really lowering the damage?

Best guess is that " Ignites as though dealing (13–364) to (20–545) Fire damage" somehow counts as a hit since it ignites on hit, but do take this over to the bug report forum to report the bug, might just be a display bug.