Maybe thats because he has a "detection area", so when you enter that area and you are hidden, he don't notice you are around, unless you get out of that area and enter it again. I thought about fixing this, but i think the game is hard enough as it is haha
But, what I'm trying to say is that with that encounter, I was in the detection area and he didn't acknowledge me and stood there for 2-4 seconds before moving on.
I have another encounter in which I come out of the table, I crawl my way to the hallway then the Ayuwoki's there, so I back up looking at him and he bugs out and stands still for a solid 10 seconds before moving again, and I have another similar encounter where the Ayuwoki literally comes up to me when I'm in the satanic circle and just leaves when he's clearly seen me. Still playable tho