I have only really noticed this on my cleric. profile is the defiant 6-30 happens on wolves and boars the mob vanishes or looks like they get sucked under the ground, bot still running but character stays in place for a long time till heading to next hotspot, then the agroed mob rubber bands out from under the ground and he finishes him off. I don't know that much about how this software works but its almost like the mesh is altering the AI of the mobs, which if the case could make botters stick out like a sore thumb.
its all class's btw not just clerics, only seems to happen to me after being online for a super long time if i restart my game it will work fine