Four hidden buttons don't react to my shots. i have used different types of arrows, but nothing helps.
I FOUND THE WAY TO FIX IT. USE AARD!!!

Was going to say that but was ninga'd,I think that is the word.

I first attempted this side quest a week ago, i got slaughtered repeatedly, so like I would do with any other quest, i left to level up and went back later. Now, nothing triggers, I walked right past the barghests, the stones do nothing...it was a week ago, I have multiple saves since then. Is there anything that I can do or am I just out of luck for completing this now?

There is a stone that is way out of reach for Aard. You need to find it and use your crossbow.

i used ard on 3 of the stones but the one across the chasm is to far away. i tried using my crossbow and burned through over 50 arrows and it still didn,t activate. went looking for exploding bolts but none of the blacksmiths make bolts that i could find. doesnt anyone in this version of the game make bolts? would like to know why my crossbow won,t activate the stone. i,m level 42

i would appreciate it if someone could help with turn and face the strange

I just saw a video of someone using Aard to hit the last switch, you just have to stand on the closest railing. https://youtu.be/eYShfIlFaBw

Also, I searched some old threads and some people hit the fourth switch with bombs instead, so try that.

thank you johnbrownxr20 i was able to open the door with grapeshot bomb and i finished the quest. thanks again for the help!!!

You're welcome, glad to hear it worked for you.

I did it, with the crossbow: did you try changing to the default, unlimited bolts?