I was following this
video on youtube
Everything fine until i had to go to the labyrinth at the dionisic games... like, it's a labyrinth and the note's location is random, so... yeah.
Also, i remember having to look around a little at certain aiodos camp because i couldn't find the note at the same spot as the video.
You will have to keep looking around the alleged note's location.
Credit goes to "SadMelodie" for sharing the video with me and others.