I'm now redesigning the cave so it stands out more.
Hmm... no clue what caused that first issue.
The bottom right artifact is a hook, found in level 4.
To the right of the ladder is a magic key, found in level 9.
I'm submitting an update soon that hopefully addresses a LOT of these issues.
Here is a thought. I was standing on the left side of the room facing the trigger and the beam reflected through the arrow, Could have done something, I don't know
It is a game stopper for me.