That has been a problem since EA, invisibility while solo still stuns the entire map, enemies wont even search you.
Obviously the only solution is that if a player enters Stealth, the game should immediately exit and uninstall itself.
i think we can at least do some middle grounds here if the game advertise intelligent AI design, i mean freaking use a rain spell in the immediate area you were standing for gods sake.
It is illogical that if you are invisible = enemies stunned.