Well, I already set trace height of the trace as 50. The character on the right side of the picture thinks he is not visible from the left character, since his trace test hits the cover laying in front of the left character.
Why don’t you try parallel to cover direction test? Set “EQS_GetTargetActorsSameClass” as its context and play around with epsilon value(maybe 0.1 to 1 not 0). In my case, AI characters find out right side of covers against their target pawns. Though they don’t react smoothly if their target pawns move to their flank, I think it works better than AI Behavior Toolkit’s default shooter EQS AI.