I'm trying to replicate on my party members, and I'm not seeing the large red "negated" text in the attack roll. It may be Spell specific. I had my PC on high ground, shadowheart shooting a crossbow from low ground. Shadowheart hiding negated the low ground. I enwebbed my PC and Shadowheart's aiming percentage estimate showed two green arrows, one red arrow, but the hit percentage is not adjusted for having +1 advantage. I am currently unable to replicate the situation described in my previous post (everything is dead), so I will have to start a new playthrough.