Shriekers are invisible and untargetable - FOUND A WORKAROUND

EDIT:I managed to find a "solution".By going straight for the Shriekers in act 3 as soon as I arrived, I was able to see them: https://i.imgur.com/dgRRwFq.jpg This means that the shriekers will appear (altough bugged on the ground) only for the very first time you load into the area, if you then reload any save game made in that area, the shriekers will turn invisible and untargetable for the rest of your playthrough.The ones in act 1 and 2 are easy to get past with teleport abilities, but it's not really the same for Act 3, luckily it's very easy and fast to get to them once you arrive on the island and you should purge them as soon as you get there (don't use source vampirism on them, they have a wonky range and will lock onto you from further away for some reason).If you die you will need to reload a save from act 2 and go into act 3 once again, otherwise they will turn invisible.You can technically use this method for the ones in Act 1 and 2, in act 1 it takes long before you can purge them, and you also would need to do the entire thing in one session without ever reloading a save file; as for act 2 you could be able to speedrun to them by going to the graveyard and teleporting down on the docks, and possibly kill also the one in the cave, altough enemies are level 13 there and you will be at level 9 at most. Good luck if you intend to try that.TL/DR:-Before departing for the Nameless Isle (Act 3) save your game, once you are on the island go straight to where the shriekers are, you should be able to see them-Use Purge on them (if you don't have a purging wand you can find one on a black ring soldier corpse on the way to the shriekers, or by killing black ring necromancers, they usually carry one)-There you have it, remember to save immediately after killing them then proceed on exploring