Game Mechanics: attacked orc on hill

[bakkily]

k in cb, by the moat to the left of the bridge is a hill, so i pulled a lego up onto this hill and started to attack it, first thing i did was doting the mob, while i was on the hill he ran up, and once he ran onto the hill no dmg was being done, this isnt trainer hill, the one more left to the castle, and i nuked him twice, with no dps being done, and with melee on was doing no dps either, just decided to post here about it being a bug